ScottJeep Posted November 15, 2014 Share Posted November 15, 2014 Nothing like waiting til it's COLD. The fan doesn't work on any settings. The fan area in the engine compartment looked like rodents had nested there when I bought the truck. Pulled the fan. Cleaned it, checked area at firewall. Looked OK. No signs of leaky heater core. Wiring had been chewed. Taped back up with electrical tape. Applied voltage at connector directly from the battery and the fan spins very well. Checked wiring at dash controls. Tan wire had melted the plastic connector. Found posts about melted connector. Found near pristine connector at local PullAPart cut connector and wiring from PAP Jeep. Had to cut wiring out of old connector. Was able to saving wiring. Moved wires over to the to the new junk-yard connector. After these basic checks I still have no fan, in any fan switch position. No blown fuse. Basic checks with volt-meter seem to indicated no voltage across fuse location. Have swapped the fan switch and resistor pack sill nothing. Feel like I am over-looking something simple. Link to comment Share on other sites More sharing options...
gogmorgo Posted November 15, 2014 Share Posted November 15, 2014 You think it's cold where you live? I spent a couple days with the heater core bypassed in my daily driver because the heater plumbing decided it preferred to heat the interior by dumping all my coolant into the passenger footwell... Waiting till it's cold, alright. And it's still a relatively warm 9°F here. Honestly glad that happened now instead of in a couple months. At any rate, the circuit that gives power to the blower fuse also runs the radio (cigarette lighter), and turn signals and backup lights. If those are still working and you aren't getting power to the blower fuse, then the problem lies in the fuse panel. If those also aren't working, then a good place to check would be the brown wire leading from the ignition switch. Link to comment Share on other sites More sharing options...
ScottJeep Posted November 15, 2014 Author Share Posted November 15, 2014 Well the cigarette lighter worked last time I tried to charge the mobile phone, the turn signals work but the back-up lights DO NOT and I have tried the common stuff there...NSS....TCU fuse maybe you are onto something with the wire from the ignition switch.. Thanks for the response...try to keep warm! Link to comment Share on other sites More sharing options...
ScottJeep Posted November 15, 2014 Author Share Posted November 15, 2014 Still attempting to trace this issue down. Checked the brown wire on the ignition switch. MAN WHAT A PITA TO GET TO AND GET UNPLUGGED! Thought I remembered seeing a post about this portion of an ignition switch getting fired and the plug looked just a bit "not right". I had recently torn down an old steering column so....... swapped over the ignition switch from it and.....nope Still no fan blower. Cig lighter and radio still works. Did come back across more wiring/connectors that I think have an impact. One is a three connector TAN, BLACK/YELLOW and BLUE/YELLOW. The Blue/Yellow goes up to the top of the brake pedal...this has SOMETHING to do with the TCU and torque converter lock-up and I am sure this is part of another little issue I have. Link to comment Share on other sites More sharing options...
ScottJeep Posted November 15, 2014 Author Share Posted November 15, 2014 Any chance anyone has a PDF of the 89' Electrical?????? Looks like I have some tracing and metering to do...and the wiring appears to have changed between 88' and 89'. Which makes some sense since the 101 connector was eliminated. I am at a point that I think the first order is tracing the 12V feed. I have two connectors that I am wondering about as well which I think have some other impacts... This one....connected somewhere in the AW4 wiring it shares cable colors with the switch at the top of the brake pedal. And I found someone else ran into this wiring before.....http://comancheclub.com/topic/42778-high-idle-no-converter-lockup-etc-need-bigtime-help-please/page-2 But I can't quite figure out where mine it suppose to go/be. I don't have/haven't found the 6 pin connector in the above post. Link to comment Share on other sites More sharing options...
gogmorgo Posted November 15, 2014 Share Posted November 15, 2014 I'm mostly just looking at '88 wiring diagrams in my suggestions. For chassis (non-drivetrain) stuff they've mostly been accurate for my '91, wire colours aside. They're the sme pdf package that's been floating around on here, and can link to them if you want. If you've got power to the other stuff running off the same circuit in the fuse panel as the blower motor, but not to the blower fuse itself, then it's a pretty good guess that your issue lies in the fuse panel somehow. The reverse lights share the turn signal circuit (and fuse). If the turn signals work, then your reverse light issue probably isn't related to your blower issue. I don't really have any experience with the electrical side of the heater/blower stuff in the MJ, though, and am basing most of what I'm saying off the afore-mentioned diagrams, which as you suggest may not be entirely accurate. In other news, I've successfully replumbed my heater, so I'm staying warm again. Still need to figure out what to do with the antifreeze-soaked carpet, though... Link to comment Share on other sites More sharing options...
ScottJeep Posted November 15, 2014 Author Share Posted November 15, 2014 Thanks for the replies thus far.... Pulled fusebox off firewall inside...fun stuff.... BROWN from Ignition does supply the 12V over and it's there and it is transferring to the VIOLET/YELLOW which then appears to be applied to the A/C / HEATER switch unit on the top. Here is where it got real interesting.... in probing the LEFT VIOLET/YELLOW there was indeed 12V AND In the middle of this probing ALSO touched the LIGHT BLUE wire....WHEN I DID THE FAN KICKED ON! IF I adjusted the FAN SPEED switch and jumped those two wires again the fan worked. Well it was actually backwards which was slightly puzzling but that might just be the thumb piece is upside down is my guess. SHOULD I pull the whole switch assembly and check for continuity thru the switch? Link to comment Share on other sites More sharing options...
ScottJeep Posted November 15, 2014 Author Share Posted November 15, 2014 *****FIXED***** Took complete switch assembly out. Cleaned everything I could. Added "just a little" WD-40 to the internals of the switch. Worked it. Worked it. Worked it. Double checked EVERYTHING again. Double checked fan switch for proper setting of the thumb piece. Connected ONLY the electrical connections. BADA BINGO! WORKING. Thanks gogmorgo for your replies. Sometimes when you are working on something by yourself like me you just need some extra input to keep you going. Now I gotta figure out what that other wiring connector off the brake pedal does. I know it has something to do with the TCU and transmission. Maybe even my mysterious no reverse lights. Link to comment Share on other sites More sharing options...
gogmorgo Posted November 16, 2014 Share Posted November 16, 2014 Not sure I entirely followed everything you did there, but glad I could help? :dunno: :thumbsup: Good to hear you got it fixed. Driving with fogged up windows because you can't put heat onto them sucks serious balls, not to mention is downright dangerous. Trust me, I know first hand from very recent experience! Link to comment Share on other sites More sharing options...
Jeep Driver Posted November 16, 2014 Share Posted November 16, 2014 *****FIXED***** Took complete switch assembly out. Cleaned everything I could. Added "just a little" WD-40 to the internals of the switch. Worked it. Worked it. Worked it. Double checked EVERYTHING again. Double checked fan switch for proper setting of the thumb piece. Connected ONLY the electrical connections. BADA BINGO! WORKING. Thanks gogmorgo for your replies. Sometimes when you are working on something by yourself like me you just need some extra input to keep you going. Now I gotta figure out what that other wiring connector off the brake pedal does. I know it has something to do with the TCU and transmission. Maybe even my mysterious no reverse lights. No lights could be the NSS. The other wire off the brake pedal could be to unlock the shifter from park. Link to comment Share on other sites More sharing options...
gogmorgo Posted November 16, 2014 Share Posted November 16, 2014 The other wire off the brake pedal could be to unlock the shifter from park. Possibly, but to my knowledge, no such wire/cable exists. On my '91 it didn't. The only two cables on my shifter were the shifter cable itself, and the ignition lockout. I could throw it into gear without stepping on the brake. The things off the top of my head that I believe wires on the brake pedal of a vehicle from this period would be most useful for would be: brake lights, cruise control shut off, and torque converter unlock. I can also potentially see a remote starter vehicle shut-down, but they look too factory for what wouldn't have been a factory option. I'd say the TC unlock is most likely. Link to comment Share on other sites More sharing options...
ScottJeep Posted November 16, 2014 Author Share Posted November 16, 2014 !!!!SECOND MYSTERY SOLVED!!!! Thanks for the input. I had not indicated but had done the NSS rebuild way back. gogmorgo... mine is the same I can drop the column shifter as soon as I unlock the ignition switch. In the middle of laying VERY uncomfortably in the driver's floor board putting everything back together I found the other connector to this... and MADE THE CONNECTION.. The other end I caught out of the corner of my eye...way up behind the gas pedal. You can just see in my crappy picture... comes out of the LARGE wiring loom. I would have never found this just looking under the dash had to get all down in there. Instantly REVERSE LIGHTS and it definitely has something to do with the TCU and TC Unlock. Took truck for ~6 mile test loop. Ran better than ever and had to turn the heat OFF on the way back! It's been a long weekend in the dash but very happy with all my results....HEAT, Pioneer Bluetooth head unit, and all my wiring figured out and more things WORKING!!!! Link to comment Share on other sites More sharing options...
gogmorgo Posted November 17, 2014 Share Posted November 17, 2014 :cheers: :clapping: :rock on: . :MJ 2: . :group beer: :driving: :jump: Congrats! I always hate working under the dash... at least you don't have a floor shifter to deal with in there like my MJ. Sometimes I find it easier to lay across the truck instead of out the door. Some of the stuff in the Lada required me to lay across the tranny tunnel for access with both hands, couldn't get at it properly through the door, and with a footwell full of antifreeze there was no way I was risking getting my hair in it. Been there done that too many times. The Lada has not one, not two, but THREE shifters that all want to go for my kidneys it seems. Silly Soviets, simplifying things by making them more complex, and then not building them properly... Sometimes I wonder why I drive this POS. Then I laugh at myself because that's really what it's all about. A fun and unique winter beater that keeps me busy. But it really makes me miss driving my MJ... I need to do something about that motor ASAP. A few years back I discovered that it was easiest to get at stuff to change the blower motor in my parents Impala when I was completely upside-down in the seat, with my feet in the air. My Dad walked into the garage to see how I was doing, took one look at me with my knees hooked over the top of the seat back, and walked out. I heard him roaring with laughter all the way upstairs in the house. :teehee: Link to comment Share on other sites More sharing options...
Virginia Posted September 29, 2016 Share Posted September 29, 2016 OK, I'm having the problem of no blower, blinkers, horn in my 88 comanche. I need you to treat me like an idiot and walk me step by step on how to diagnose this please. Link to comment Share on other sites More sharing options...
Pete M Posted September 30, 2016 Share Posted September 30, 2016 did they all stop suddenly together? Link to comment Share on other sites More sharing options...
Virginia Posted September 30, 2016 Share Posted September 30, 2016 Yes, they did. Link to comment Share on other sites More sharing options...
yxmj Posted September 30, 2016 Share Posted September 30, 2016 As mentioned above...they are on the same circuit...check the fuse Link to comment Share on other sites More sharing options...
Virginia Posted September 30, 2016 Share Posted September 30, 2016 I've checked the blower fuse under the dash and it's fine. I pulled what I think is the correct resistor under the hood and it looks fine but I know that's not definitive but I don't think it's the resistor because I don't get blower when the switch is on high. If there's another fuse, I can't find it. Link to comment Share on other sites More sharing options...
Ωhm Posted September 30, 2016 Share Posted September 30, 2016 Resistor under the hood, could be FP. (fuel pump) Link to comment Share on other sites More sharing options...
Virginia Posted September 30, 2016 Share Posted September 30, 2016 There is a bank of 4 resistors under the hood over by the battery. Link to comment Share on other sites More sharing options...
yxmj Posted September 30, 2016 Share Posted September 30, 2016 Resistors.... Do you mean relays? Link to comment Share on other sites More sharing options...
Virginia Posted September 30, 2016 Share Posted September 30, 2016 Resistors.... Do you mean relays? Yes, sorry. Link to comment Share on other sites More sharing options...
Ωhm Posted September 30, 2016 Share Posted September 30, 2016 Do you own a 12vdc Test Light? Link to comment Share on other sites More sharing options...
Virginia Posted September 30, 2016 Share Posted September 30, 2016 Yep Link to comment Share on other sites More sharing options...
Ωhm Posted September 30, 2016 Share Posted September 30, 2016 Is vehicle equipped with a factory radio, and does it work? Link to comment Share on other sites More sharing options...
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