WD21colorado Posted July 2, 2014 Share Posted July 2, 2014 So Im trying to get the blower to work again threw the existing hardware. and trying to make the ac work. I did a voltage check for the blower motor and im getting some weird numbers. the highest the voltmeter was showing was about 11.2 volts ( engine running) and it doesn't seem to change when you adjust the fan speed. and it only gets more strange. when you engage the ac the engine electronics still work. but the compressor doesn't engage. and the voltmeter readings go from 11.2 volts and it drops down to about 2.2 - 2.5 volts. So I know I have a voltage problem. so I was thinking that IS it possible to run a fused hot wire to the climate control fan speed. because it seems like my vehicle has some unknown voltage problems like the original 12 volt plug in only showed 9.7 volts whether if the engine is running or not. so it would be nice to know what you guys think of this problem. Link to comment Share on other sites More sharing options...
Slartibartfast Posted July 2, 2014 Share Posted July 2, 2014 Okay, so, a few issues here. The blower voltage not changing with fan speed does not surprise me. The device that controls the fan speed is just a resistor pack, and at low currents, resistors aren't very effective. Given how low the resistances in the pack are, and how high the resistance of your meter is, you're likely to see full power on any setting--it's when you start drawing power (with the fan motor) that the resistor pack comes into play. If you want to see it change, you'd have to test across the terminals of the fan while it's running. I would not expect to see full battery voltage at the fan connector, but 11.2 with the engine running is low. Sounds like the compressor clutch isn't getting enough juice to engage fully, and it's overwhelming the circuit when it tries. There's clearly a bad connection somewhere. My bet is a bad ground under the dash somewhere (which running a new + line wouldn't help). Find which pin of the blower is ground, put a test lead from that to ground, see if the voltage on it comes up? Also check out your fuse links (on and around the positive terminal), the terminals themselves, and whether the battery's got a full charge. A battery dead enough to cause your problems would probably not start the thing, but it's good to rule it out. Wiring's always fun to sort out... hopefully it's just a loose bolt somewhere. Link to comment Share on other sites More sharing options...
WD21colorado Posted July 2, 2014 Author Share Posted July 2, 2014 the battery is still good. it registers 12.5 with the engine off and 13.62 with the engine idling. and for the blower motor. it wont run on any of the fan settings. but the volt meter is showing 10.4 volts but nothing more. so Im going to see what the voltage is showing in the fan speed unit. Link to comment Share on other sites More sharing options...
Terranovation Posted July 3, 2014 Share Posted July 3, 2014 Maybe try cleaning out the hole where the resistor goes into the plastic housing. I know leaves and things can get stuck in there. Maybe it's clogged up so much the blower motor is stressed out. Link to comment Share on other sites More sharing options...
WD21colorado Posted July 3, 2014 Author Share Posted July 3, 2014 Ive done that last week. There was a few leaves in there. But i found out that the main positive wire is only doing about 9.7 volts. So I'm going to try and run a fused hot wire to the blower controls Link to comment Share on other sites More sharing options...
Slartibartfast Posted July 3, 2014 Share Posted July 3, 2014 You can check the blower motor right off the battery, if it spools up with the full voltage, then it's fine. They do wear out but it sounds more like that + wire is just too shot to power it. Good luck with the fused lead, hopefully that gets it going. Link to comment Share on other sites More sharing options...
WD21colorado Posted July 5, 2014 Author Share Posted July 5, 2014 The blower motor works. But not getting enough current to run the motor. And the plan with running a hot wire didn't work so have to plan something else. Link to comment Share on other sites More sharing options...
Terranovation Posted July 5, 2014 Share Posted July 5, 2014 It must be the blower motor so you'll need a 2nd hand one from a wreckers Link to comment Share on other sites More sharing options...
WD21colorado Posted July 5, 2014 Author Share Posted July 5, 2014 the blower motor still works. when it has direct current from the battery or a good power source. but the voltmeter is showing thats the plug is getting way to little current. Link to comment Share on other sites More sharing options...
Terranovation Posted July 5, 2014 Share Posted July 5, 2014 Hmm ok. Maybe it's the resistor then. What happens from what I've been told is that the current is actually less when the fan is set to 1 or 4. Leaving the fan set to 2 or 3 can wear the resistor out if you leave the fan on for long periods of time. I remember reading that the resistor can heat up if left in position 2 or 3 for a long time. Link to comment Share on other sites More sharing options...
Alkorahil Posted July 7, 2014 Share Posted July 7, 2014 (edited) So from what I am gathering here, the AC switch comes on fine (light up green) the bloaser is not working properly. This sounds like a blower motor resistor or fan speed switch issue as they both control voltage to the blower. The most common symptom of a bad resistor is the fan will only blow on high speed no matter which of the four settings the fan switch is on which doesnt fit your issue exactly. The fan switch is a simple switch. Moving the indicator from one position to another moves the switch accross copper contact points. The higher the setting the larges the copper point the switch makes contact with. The larger the contact, the more currect can flow accross the connection. These conacts in the switch can corrode over time, reducing or even eliminating the quality of the connection and thus the amount of current that can flow across the connector leads in the switch. If you remove the instrument bezel you can pull (carefully) the face plate of the AC controller. Move the swtch to 'off'. With a flashlight you can see your switch connectors and see if they are corroded/green. Edited July 7, 2014 by Alkorahil Link to comment Share on other sites More sharing options...
Slartibartfast Posted July 8, 2014 Share Posted July 8, 2014 If it's getting power fine from the + side, that leaves a bad ground. Not too hard to check, just run a wire from the - side on the motor to a known ground--bare metal under the dash, the pin for the door holder-opener thingy, whatever's handy. So if the + lead is good, and the - lead is good, and your motor is good, then either the switch is shot, or the resistor pack is shot. My understanding of the speed switch is that the actual current reduction is done by several resistors (the resistor pack), which the switch engages in different configurations depending on the speed selected. More resistors = less current available to go through the blower motor, so the lever just wires the resistors in or out. So 1 would be all the resistors, 2 would bypass one of the resistors, raising the current, three would be just one resistor, higher current still, and 4 would be all four resistors bypassed (full power). Those resistors do heat up with current, and are known to start fires when the air box fills with leaves and pine needles--my '95 has a sort of shield to prevent this, but apparently the early models didn't. Anyway, try bypassing that (it's the thing sunk into the air box behind the glove box, pretty near where the motor's at--look for the pinned thread on cleaning it if you can't find it) if the ground checks out. You have the manual climate control with the fan speed slider, not the automatic one with the temperature slider, right? Link to comment Share on other sites More sharing options...
Terranovation Posted July 8, 2014 Share Posted July 8, 2014 This video may help. It shows how to take the panel off and also explains that if you don't push in the plug side when reinstalling (where the air con button is) it won't light up and activate when you press the a/c button. Link to comment Share on other sites More sharing options...
WD21colorado Posted July 10, 2014 Author Share Posted July 10, 2014 sorry that I haven't replyed in a while. anyway the climate controls is MANUAL NOT AUTOMATIC like in the 1996 version. 1995 pathfinder is what I have. so far I have checked the reistor block. it shows on the voltmeter that it is still working so far I have checked the main grounds for the truck and there still clean Iv'e also have checks the ac clutch relay along with the other parts that should make it work. still cant figure out why it doesnt push enough current. Iv'e also notice that the original 12 volt socket plug and the power mirrors are showing the same problem both of those things are only getting less than 9.7 volts. so If anyone else has ran into this problem please let me know. Link to comment Share on other sites More sharing options...
Slartibartfast Posted July 12, 2014 Share Posted July 12, 2014 Some WD21s did come with auto climate control--saw one in a '93 at a wrecking yard. I haven't worked with one but they look like a PITA to troubleshoot. Doesn't sound like the problem is in the climate control system, though. Multiple things down on voltage suggests that the problem is the same between them. Have a look at the EL section of the FSM and see if you can find something in common for those systems--a ground point, a fuse link, a body harness connector, something like that. If the connection's bad enough that the meter is reading low voltage, it shouldn't be too hard to pin down the problem. Link to comment Share on other sites More sharing options...
WD21colorado Posted July 14, 2014 Author Share Posted July 14, 2014 Alright so strange thing happened. Was 4wheeling last Friday. And drove over a Fairly large rock. And all of the sudden i regained power to my climate control and the rest of the non working components. But it seems like it's tied to the wiring harness that powers the 12 volt plug wire, climate control and rear window wiper and acts like it's either a loose ground or faulty relay. So does anyone one know what ground location or relay that powers the power mirrors, climate control and rear window wiper. Link to comment Share on other sites More sharing options...
WD21colorado Posted July 22, 2014 Author Share Posted July 22, 2014 alright so I found out what was the problem with the 12 volt circutry. it turned out to be a intermitten fault with a relay that was replaced a couple of weeks ago. but as for the compressor clutch is still not engaging. along with the engine not picking up on idle speed when the ac switch is engaged. Link to comment Share on other sites More sharing options...
WD21colorado Posted July 22, 2014 Author Share Posted July 22, 2014 It's finally fixed now. it turned out that their was a plug that wasn't pluged into a thermo sensor on top of the heater core that was causing the problems. now the full HVAC system works. Link to comment Share on other sites More sharing options...
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