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Electrical System Shut Down


V8path
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Looking for help with a troubling electrical problem in an 88 Pathfinder.

 

My Pathfinder has LT1 engine swapped into it, which was preceded by a Chevy 4.3L some 15 years ago (without this type of problem). So I’m thinking chances are that this is pointing to the original Nissan circuit?

 

The main electrical system has been shutting down intermittently, with the exception that (when everything else is dead) the headlights, hazard lights, dash lights (but no dash functions) and interior lights still work. The starter will not crank, no heater fan, no power windows, nothing…

 

This will happen without warning while driving, or sometimes when coming to a stop, and happens whether hot or cold.

 

Sometimes when the power shuts down, I would be able to immediately restart or restart after a few minutes of trying. When the power doesn't “self reactivate” after a few minutes, I removed and reconnecting the positive battery cable (and would hear relays clicking), the power would come back on and I was able to start the engine again. It would then either die again immediately, or within minutes, or it would run for 20 – 60 minutes without issue.

 

This has been repeating itself for a couple of weeks now. The good thing is that worst case I have been able to restart after re & re the positive battery cable. The ground cables are new and run direct from the battery ground to the body, and a second separate ground cable from the battery to the engine, so don’t think it is a ground issue.

 

I'm guessing this might or is a main circuit fault, and after searching for an 88 Pathfinder wiring diagram, I found a number of differing diagrams. One of them shows a “circuit breaker” in the ignition/starting circuit, so I’m wondering if this is the problem? Anyone know anything about this part, or whether there is even one in an 88 Pathfinder, and if so, where is it (have not been able to find a circuit breaker in the majority of the different wiring diagrams I’ve found)? Also, if it is a circuit breaker issue, it could that the breaker is faulty, or is there something causing the breaker to cut power?

 

Would a faulty (key) ignition switch cause an intermittent shut down of the entire electrical system? The ignition switch is going on 29 years old.

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FYI my 88 was originally a 5 speed manual. There are some electronic component (relays and switches) variations between an auto and manual trans.

 

Also after more scouring of the various wiring diagrams, I couldn't find a second diagram that definitively shows a circuit breaker, so that's still a major mystery as to whether there is one or not in an 88 Pathfinder?

 

Am hoping someone has a good understanding of the main circuits, as I'm pretty frustrated at this point. :pullhair::headwall: It will run perfectly, than without warning, just cut out. :wtf:

 

 

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Would a faulty (key) ignition switch cause an intermittent shut down of the entire electrical system? The ignition switch is going on 29 years old.

 

This was going to be my first suggestion as I was reading it. Try some continuity checks while jiggling the keys, slight key turns, and maybe tugs on the wiring harness. Not sure if the contacts are exposed, but check for any hairline cracks on the solder joints.

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This was going to be my first suggestion as I was reading it. Try some continuity checks while jiggling the keys, slight key turns, and maybe tugs on the wiring harness. Not sure if the contacts are exposed, but check for any hairline cracks on the solder joints.

 

Hey Hawairish, thanks for the input.

 

I’ve thought that it could be a faulty ignition switch, but I was hoping to really understand the logic of that before I start to take things apart or change parts?

 

The question I have now, is why the ignition switch re-set when the positive cable was removed and reconnected? Does that (the positive cable re-connect) have some impact as to the connections at the ignition switch?

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I’ve thought that it could be a faulty ignition switch, but I was hoping to really understand the logic of that before I start to take things apart or change parts?

 

The question I have now, is why the ignition switch re-set when the positive cable was removed and reconnected? Does that (the positive cable re-connect) have some impact as to the connections at the ignition switch?

 

To answer your 2nd question first, I think it might just be coincidental that reconnecting the cables seems to reset things...but by the same token, it's very possible that some connection at the cable could also be a culprit, and a small amount of flex is "fixing" it. Any signs of corrosion, fraying, looseness at the terminals? When you say circuit breaker, and you talking about a fusible link?

 

The reason for suggesting the ignition switch is that, short of a cut cable or something more obvious at the battery or fusebox, is that it's the only moving part of the equation. It has contacts that can wear and solder joints that can crack...both of which can randomly stall, or prevent starting, the engine.

 

Here are also 3 personal experiences about the delicateness of electricity for some components:

  1. Friend's VW Cabriolet was dying randomly mid-drive. The contacts on the ignition switch had worn down...the tiniest key wiggle would not only shut off a running car, but would prevent it from starting if at just the slightest incorrect position (pulled the fuel pump fused, and listened to it pause during cranking with tiny key movements in the Start position).
  2. On my Frontier, I had a Clifford Immobilizer. The heavy gauge wires for the ignition switch run through it, and one day, my truck mysteriously died in an intersection (when my parents were driving, no less). Happened to me very randomly over a few weeks, but could seemingly always start it up immediately after. It died around a turn one day, couldn't restart it. Traced it to the Clifford unit...tiny hairline solder fracture on the circuit board was the problem. Although it wasn't directly an issue with the ignition switch, the implication is clear.
  3. On a Infiniti J30, the headlights kept shutting off randomly. Usually stayed on, sometimes flickered. Took me HOURS to find this tiny headlight control module with...you guessed...a cracked solder joint inside. Not ignition related, of course, but similar random electrical issues.

I do a fair amount of soldering on various other projects, and usually when I have unpredictable electrical problems, I pull out a magnifying glass and check the solder joints first. Doesn't take much to open a circuit. Even had a similar problem on one of my kid's toys recently. Simple fixes, but tedious to locate.

 

Bottom line is that a tiny solder crack can cause a myriad of odd symptoms, but there are also contacts that just wear down sometimes. And the ignition switch is the first point in the circuit with them, so that's the basis for the suggestion. Replacements are pretty cheap, though I'm not sure if yours would be screwed or riveted on (I want to say the one on my Frontier is only screwed on).

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To answer your 2nd question first, I think it might just be coincidental that reconnecting the cables seems to reset things...but by the same token, it's very possible that some connection at the cable could also be a culprit, and a small amount of flex is "fixing" it. Any signs of corrosion, fraying, looseness at the terminals? When you say circuit breaker, and you talking about a fusible link?

 

The reason for suggesting the ignition switch is that, short of a cut cable or something more obvious at the battery or fusebox, is that it's the only moving part of the equation. It has contacts that can wear and solder joints that can crack...both of which can randomly stall, or prevent starting, the engine.

 

Here are also 3 personal experiences about the delicateness of electricity for some components:

  1. Friend's VW Cabriolet was dying randomly mid-drive. The contacts on the ignition switch had worn down...the tiniest key wiggle would not only shut off a running car, but would prevent it from starting if at just the slightest incorrect position (pulled the fuel pump fused, and listened to it pause during cranking with tiny key movements in the Start position).
  2. On my Frontier, I had a Clifford Immobilizer. The heavy gauge wires for the ignition switch run through it, and one day, my truck mysteriously died in an intersection (when my parents were driving, no less). Happened to me very randomly over a few weeks, but could seemingly always start it up immediately after. It died around a turn one day, couldn't restart it. Traced it to the Clifford unit...tiny hairline solder fracture on the circuit board was the problem. Although it wasn't directly an issue with the ignition switch, the implication is clear.
  3. On a Infiniti J30, the headlights kept shutting off randomly. Usually stayed on, sometimes flickered. Took me HOURS to find this tiny headlight control module with...you guessed...a cracked solder joint inside. Not ignition related, of course, but similar random electrical issues.

I do a fair amount of soldering on various other projects, and usually when I have unpredictable electrical problems, I pull out a magnifying glass and check the solder joints first. Doesn't take much to open a circuit. Even had a similar problem on one of my kid's toys recently. Simple fixes, but tedious to locate.

 

Bottom line is that a tiny solder crack can cause a myriad of odd symptoms, but there are also contacts that just wear down sometimes. And the ignition switch is the first point in the circuit with them, so that's the basis for the suggestion. Replacements are pretty cheap, though I'm not sure if yours would be screwed or riveted on (I want to say the one on my Frontier is only screwed on).

 

All good points to consider.

 

I have one more, and hopefully someone has experience with the wiring circuitry to know if this is a more likely source of the problem.

 

The re and re of the positive cable is the basis for looking at this.

 

There is a ignition relay in the circuit (its location is supposedly - from the diagrams) near the fuse block. As there has been a consistent ability to re-start after re and re the positive cable, it was suggested to me that it could be a sticking relay that gets re-set when the power is removed, then reintroduced by the re and re of the positive cable.

 

What do you think?

 

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Does yours still have the original fusible links at the battery? They are little sections of wire with connectors on each end. They are known to cause these kinds of issues and would explain why playing with the positive terminal "resets" things. Next time it dies try playing with those.

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Any signs of corrosion, fraying, looseness at the terminals? When you say circuit breaker, and you talking about a fusible link?

 

 

 

My reference to a circuit breaker was from what I found on a wiring diagram. Not sure how accurate it was, and I've not been able to find that (at least not yet).

 

Does yours still have the original fusible links at the battery? They are little sections of wire with connectors on each end. They are known to cause these kinds of issues and would explain why playing with the positive terminal "resets" things. Next time it dies try playing with those.

 

On a visual inspection, the fusible links at the battery terminal look to be in good shape for 28 - 29 years. Will definitely have a 2nd look and test them if there's anything suspect.

 

Hoping someone has some intel/experience with the ignition relay?

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Hoping someone has some intel/experience with the ignition relay?

 

If the relay isn't unique for your setup, do you have another you could swap it with? Could always test the relay, too, but sounds like it would only fail intermittently. Could take it apart to check for corrosion or any residue from arcing.

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If the relay isn't unique for your setup, do you have another you could swap it with? Could always test the relay, too, but sounds like it would only fail intermittently. Could take it apart to check for corrosion or any residue from arcing.

 

Well now I'm really baffled.

 

I removed the ignition relay and thought to crank it over. IT RAN!!!. btw the acc relay and the ign relay are identical.

 

I can only think it would run due to (as I'll have to go back and look at what I did 15 years ago to confirm for sure) that the (earlier 4.3L which is now the) LT1 PCM was wired separate from the Nissan circuit, but I'm pretty sure whatever I used for a power source for the LT1 PCM came off a existing Nissan circuit. Otherwise, why would the engine not crank over when everything else went dead as described in the opening post.

 

I checked the ignition switch and played with the connections and the contacts, which are clean and firmly soldered. No visible faults/cracks etc. There was some play however between the back of casing where the contacts are soldered, and the main tumbler casing, but when jiggling it and tugging on the wires, contact was not broken (had a test light attached while I did this). The key however is loose inside the key slot, but operates as it should in all positions, and it didn't affect the current flow.

 

I'm baffled :headwall:

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The loose key in the slot is probably normal, as the key and tumblers have worn down over time (the keyed part is just for the steering wheel lock anyway; it's the key's tip that engages the ignition switch).

 

In re-reading your original post, can you confirm something for me? The systems that were on seem like those that would be available if the ignition were turned to the ACC position (noting that headlights and the hazards should always work, regardless of position), right?

 

I don't know specifics about an 88, but it's usually the case that AC/fan, dash functions, and power windows don't work until the ignition is in the ON position (truck started or not). The ignition also returns to ON after starting the truck and must remain ON, of course. My thought is that if the truck returns to an ACC state and not an ON state when it stalls, instead of staying in an ON state when the key is still pointing to it, then I'd still be suspicious of the ignition switch. If it's anything else (like a bad relay, engine/mechanical failure) it would stay in ON in theory.

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  1. On my Frontier, I had a Clifford Immobilizer. The heavy gauge wires for the ignition switch run through it, and one day, my truck mysteriously died in an intersection (when my parents were driving, no less). Happened to me very randomly over a few weeks, but could seemingly always start it up immediately after. It died around a turn one day, couldn't restart it. Traced it to the Clifford unit...tiny hairline solder fracture on the circuit board was the problem. Although it wasn't directly an issue with the ignition switch, the implication is clear.

 

I think you might have something re the immobilizer.

 

I have a older Alpine security alarm (over 15 years old) that was installed by the shop where it was purchased. A few weeks ago, I noticed that the lights that normally flashed (along with a short chirp from the alarm) when the alarm was activated and deactivated were not working, but the lock open and close function still worked. I didn't think much of it at the time.

 

As the pieces covering the steering column were already apart, I decided to peak a bit further under the dash and noticed a relay attached to the alarm unit. I pulled it out to check the connections (which were clean) and plugged the relay back in. Tried the alarm, and the flashing lights and the chirp worked.

 

I replaced the relay.

 

Unless I find something else, perhaps this (a faulty relay) was the issue all along? Or might it be the alarm unit?

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Unless the alarm has an immobilizer and/or remote start feature, it's likely not the problem. If you don't see any thick wires coming from the alarm module (i.e., those that might be capable of handling high currents), then it's probably just used for arming/disarming. Although it might have an input for ignition sensing for some functions, none would (should) be capable of stalling the truck.

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The alarm is about 15 years old, and I really don't know if it has an immobilizer feature.

 

Looking at the wiring for answers, the alarm unit is spliced into the battery and ignition wires (spliced but not separating the key and the ignition system). The ground wire however was separated, which is pretty odd, as any starter of ignition kill would normally have the alarm unit in line between the key and starter or ignition component.

 

If this is not the source of the power shut off, I'm at a loss of what to look for next?

 

 

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In re-reading your original post, can you confirm something for me? The systems that were on seem like those that would be available if the ignition were turned to the ACC position (noting that headlights and the hazards should always work, regardless of position), right?

 

I don't know specifics about an 88, but it's usually the case that AC/fan, dash functions, and power windows don't work until the ignition is in the ON position (truck started or not). The ignition also returns to ON after starting the truck and must remain ON, of course. My thought is that if the truck returns to an ACC state and not an ON state when it stalls, instead of staying in an ON state when the key is still pointing to it, then I'd still be suspicious of the ignition switch. If it's anything else (like a bad relay, engine/mechanical failure) it would stay in ON in theory.

 

Headlights, hazard lights, interior lights and dash lights don't need to be in ACC to work.

 

Power windows, fan, dash functions only work in the "run" or "on" position. ACC allows power to wipers, cig lighter, radio etc. As far as I can tell, when the power comes back on, everything is as it should be.

 

When it stalls, ACC and IGN/RUN are dead.

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I've had this issue before and it ended up being a fusible link at the battery. Mine all looked fine at a glance but we're corroded inside. I replaced them all at once and have not had the issue since. This was 5 years ago or more.

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I've had this issue before and it ended up being a fusible link at the battery. Mine all looked fine at a glance but we're corroded inside. I replaced them all at once and have not had the issue since. This was 5 years ago or more.

 

Yeah, after 29 years, they probably should be replaced anyways.

 

Its frustrating not really knowing or seeing what is causing the shut down though.

 

Worst case, a few other problems (that may or may not be the root cause) have been solved during this investigation into the wiring. Unless I find something definitively, this will likely be a case of "put everything back together" and drive it for a while and see if the problem has gone away.

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Unless the alarm has an immobilizer and/or remote start feature, it's likely not the problem. If you don't see any thick wires coming from the alarm module (i.e., those that might be capable of handling high currents), then it's probably just used for arming/disarming. Although it might have an input for ignition sensing for some functions, none would (should) be capable of stalling the truck.

 

There was a thick wire that went from the module to the relay (that I just replaced).

 

The only wire that the module separated between components, is the ign ground wire.

 

The IGN and BATTERY wires were only "tapped" into - they do not interrupt power between the module and ignition components.

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Went back and re-thought the earlier alarm issue with the lights and chirp not functioning, and was thinking maybe Hawairish might be onto something.

 

Played around with valet switch, and lo and behold, the flashing lights and chirp came back on for the 1st time in weeks. Given the alarm is 15 + years old, and all I really wanted it for was the remote/FOB ability to lock and unlock anyways, I decided to cut the alarm wire that was tapped into the ignition wire, and cut the "valet" wire.

 

Left the alarm connected to the battery wire.

 

Its been 2 days and so far, so good.

 

 

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Well so far, so good after almost a week. Is it possible a faulty alarm valet function was the cause of the system shutdown?

 

I'm still trying to figure out a few things with the ignition wiring, and the diagrams haven't been much help and hoping someone here might have the answer.

 

Am looking for the routing of the black/yellow (GND) wire from the ignition switch. This GND wire was cut when I swapped the 5 speed MT out for the 4L60E, and the GND source has been the trans shifter console mounted P/N switch. There is only GND in P or N.

 

In theory, the GND (with the MT in OEM routing) would have gotten the GND from the clutch switch - only allowing a GND when the clutch was depressed, but I can't seem to definitely identify this on the diagrams. I had zip tied the clutch pedal out of the way when the MT was replaced with the 4L60E, meaning with the clutch permanently depressed, the other end of the wire should have been permanently GND'd. There has been no issues with starting etc. since this was done (some) 15 years ago.

 

What makes this more interesting, the alarm installer tapped into the ignition GND wire (the cut end that ran behind the dash somewhere) for the alarm GND, and until recently, there has not been any problems with the alarm operation. When I saw this wiring configuration, I tested the GND wire the alarm was tapped into, and there was no GND, so that is a second mystery. I put a eyelet connector on the wire and GND's it, so I know it now is GND'd.

 

Does anyone know definitively where the GND wire from the ignition switch is routed to (or is connected to)? Knowing this will help narrow my focus, as I'd like to really figure this out for sure.

 

 

Edited by V8path
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On my '93, and in the '89 manual, black/yellow at the ignition switch should be battery + when the key is in the start position. Not ground. The alarm under the seat in my '93 has the multi connector at one side, then a smaller plug with two black/yellow wires that actually have "Starter" printed on them plugged into another side. Unplug the starter wires from the alarm and, surprise, it won't crank. Jumper those two black/yellow wires together with a paper clip and it starts right up. (Sounds like you may have a different alarm unit.) Looks like another black/yellow wire goes to the ECU, though I'm guessing that one dead-ends on yours after the V8 swap.

 

I haven't looked up the whole schematic but I suspect the wire you tested from the interlock had the other end hooked to the starter solenoid, which has its other end hooked to ground. If the shift interlock is closed, the wiring coming off it would test as ground.

 

I doubt the clutch switch is the problem, though I think I'd rig up a jumper on the electrical plug rather than just tying the pedal down.

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I think there might be changes in the wiring (which is odd) in the different years, as my GND wire is definitely the black/yellow, and my battery wire is white/red. I'm guessing these differences is what make the wiring diagrams confusing.

 

I'm still trying to figure out where the GND (black/yellow) wire runs to ... anyone know for sure?

 

The alarm is a after market unit (Alpine) installed before I did the swap, and given how it was installed, the alarm module was not wired "in between" the ignition switch and the starter or the rest of the electrical system.

 

The clutch pedal is zip tied out of the way, which leaves the switch in the always closed position, so it shouldn't affect the circuit as far as starting. But to be on the safe side, I probably should put a jumper on it so that if the switch is faulty, the circuit is closed and won't impact anything to do with the original OEM starter circuit.

 

There was also a 2nd switch on the clutch pedal assembly, but that looks to be for the ASCD (cruise control) deactivate/disrupt function.

 

 

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Hey, sorry for the hiatus.

 

Couple things worth clearing up...maybe not the case for your specific vehicle since it's got the engine swap, but notables about what I see in a few Nissans (and what I can recall from my Frontier without having it in front of me).

 

Black/Yellow per a 1989 W/D21, 1994 W/D21, and 1998 D22 is the signal from the ignition switch to the starter. You can confirm by checking the EL chapters in the Starting System diagrams. So, it's only hot when the key is at the Start position (can be confirmed by disconnecting the starter harness). One notable is that both W/D21 FSMs indicate that US-editions may actually have Black/Purple wiring, while CAN-editions have Black/Yellow. But, I also agree with Slartibartfast about possibly measuring this after the interlock switch and getting a false reading.

 

I definitely don't see anything that suggests black/yellow is a ground, and it doesn't make sense to be—the ignition switch is just a switch between the battery and the rest of the systems, so it shouldn't ground anything. But without bastardizing that wiring (and I wouldn't see a purpose to it), I'm not sure it plays into anything here since it would only impact the ability to start the truck.

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On my '93, and in the '89 manual, black/yellow at the ignition switch should be battery + when the key is in the start position. Not ground. The alarm under the seat in my '93 has the multi connector at one side, then a smaller plug with two black/yellow wires that actually have "Starter" printed on them plugged into another side. Unplug the starter wires from the alarm and, surprise, it won't crank. Jumper those two black/yellow wires together with a paper clip and it starts right up. (Sounds like you may have a different alarm unit.) Looks like another black/yellow wire goes to the ECU, though I'm guessing that one dead-ends on yours after the V8 swap.

 

I haven't looked up the whole schematic but I suspect the wire you tested from the interlock had the other end hooked to the starter solenoid, which has its other end hooked to ground. If the shift interlock is closed, the wiring coming off it would test as ground.

 

I doubt the clutch switch is the problem, though I think I'd rig up a jumper on the electrical plug rather than just tying the pedal down.

 

I'll have to have another look at the 2 black/yellow wires.

Edited by V8path
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Hey, sorry for the hiatus.

 

Couple things worth clearing up...maybe not the case for your specific vehicle since it's got the engine swap, but notables about what I see in a few Nissans (and what I can recall from my Frontier without having it in front of me).

 

Black/Yellow per a 1989 W/D21, 1994 W/D21, and 1998 D22 is the signal from the ignition switch to the starter. You can confirm by checking the EL chapters in the Starting System diagrams. So, it's only hot when the key is at the Start position (can be confirmed by disconnecting the starter harness). One notable is that both W/D21 FSMs indicate that US-editions may actually have Black/Purple wiring, while CAN-editions have Black/Yellow. But, I also agree with Slartibartfast about possibly measuring this after the interlock switch and getting a false reading.

 

I definitely don't see anything that suggests black/yellow is a ground, and it doesn't make sense to be—the ignition switch is just a switch between the battery and the rest of the systems, so it shouldn't ground anything. But without bastardizing that wiring (and I wouldn't see a purpose to it), I'm not sure it plays into anything here since it would only impact the ability to start the truck.

 

Here's a pic of the wires on the ignition switch (from top clockwise - Black/Yellow - GND, Black/White - RUN, Black/Green - START, Blue - ACC, White/Red - BATTERY)

 

IMAG2751_zpsyac2pvud.jpg

 

 

Here's a pic of the test light "on" when connected between the Black/Yellow wire and the White/Red wire (from battery - always hot). The test light only lights up when the trans shifter is in P or N.

 

There is no GND unless the trans shifter is in P or N. I then tested the light when GND'ing the ACC or RUN on the Black/Yellow (in P or N), and the test light will come on when the key is in those positions.

 

IMAG2755_zpsqwvelniv.jpg

 

 

The Black/Yellow goes from the ignition switch to the trans console P/N switch, and then from there to the remote starter solenoid.

Edited by V8path
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