WD21 interlock relay/inhibitor relay

[tmoore4512]

Okay guys, been a bit.

Looking for some insight, as I am experiencing some perpetual starting issues.

 

Pathfinder will not start unless it has a booster or a set of jumper cables connected.

 

Before you say it….

 

Brand new battery, brand new cables and connectors, brand new starter and alternator. (Literally, within the last two weeks.)

 

My next course of action is to replace all the wiring that has to do with the starting circuit, as it would appear that something is forming enough resistance that it is hindering the flow to fire the starter…

 

Which leads me to my main question:

 

In the PDF manual (#23 electrical) it refers to the “inhibitor relay” or the “interlock relay” depending on the diagram.

Does anyone know what exactly this does and is it vitally necessary?

 

Open to your thoughts.

[Frenchy]

The Inhibitor Relay is simply a starter interlock at a basic level. For an auto it will not let the starter engage unless in Park or Neutral. For the Manual it makes you push in the Clutch pedal or press and hold the interlock switch on the dash(mainly meant for OffRoad purposes for the dash switch). With what you have going on I would highly recommend getting another set of eyes on there to see what's going on. I suspect this could be something simple and silly as there is no good reason for this to happen.

[tmoore4512]

I concur with what the concept is surrounding the inhibitor/interlock relays.

 

Firmly believe corrosion is the culprit and will have to dig in deeper to see if I can locate it.

 

Thank you for the reply.

[Frenchy]

If need be take your time to clean every single ground thoroughly. I used to do Automotive Mechanics under Nissan and at the Training center in Ontario California the Instructors and Engineers stated that Nissan Has Very Poor Grounds!

[Slartibartfast]

I had an intermittent no-start or weak start on mine. It would crank slow like the battery was dead, then crank like nothing was wrong seconds later. Or the starter would run, stop, then try to start again. I replaced a whole bunch of stuff, including the starter, ignition switch, and inhibitor relay, without success. Finally I tore out the alarm and its harness. The harness intercepts the wiring from the ignition switch. In my case, it added about six feet of wire and a couple more connectors to the circuit. The alarm in the round-dash trucks moved the relay up into the dash IIRC, so the wire run should be shorter, but it's still a potential source of trouble. The weird thing was, I had already deleted the alarm brain and bypassed the starter wires in its harness, so the only thing in play was the harness. Still, the issue has been gone since I ripped that crap out.

 

Mine didn't need jumper cables to go, so I don't know that this is the same issue. If you run out of ideas, though, that's what I'd try next. The factory alarm was an afterthought and is not that difficult to remove.

[adamzan]

Have you checked those fusible links at the battery? I know you said new cables, but hey.

 

Can you jump the solenoid directly and have it roll over? That would at least narrow down where the issue is in the wiring. Mr. Reverse had a "starter fix" for these old trucks that involved adding a relay under the hood.

[tmoore4512]

All great points and things I will try next. I have not worked on this dude in years, life happens. Hell, still have all the components to do the SAS sitting there. Sigh.

But she's gotta start and run reliably first.

Thanks again.

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