Discoman9001

It was the C_157, pulled the kick panel off and found I broken wire, looks like it got cut by the parking brake. Thanks for the help everyone!

So update, I tested the 104_k and on the truck side when I put in reverse I get my 12v power and when I put powere through the opposite way (which should light up the lights) I get no lights, I’m assuming the under the hood wiring from the connecter to the fuse box which goes from the relay center, across the radiator support and to the back of the fuse box must have a break somewhere in it. Gonna do some hunting and report back. Thanks everyone for the help.

So, I tested terminal E by putting direct power to it like Ohm suggested. Still no reverse lights, I checked the fuse and the plugs like cruiser54 said. And still no lights… any more suggestions?

Hello everyone, i am once again coming to the forum in search of guidance because i am at a loss with my Comanche, i will try to be a thorough as possible with the work i have already attempted on this beast it is a 1988 comanche with Automatic transmission and 4X4. Not to long ago my reverse lights stopped working for seemingly no reason, originally it was a blown fuse 7.5 labelled trans under the dash, so i replaced it and the fuse instantly blew again, so i chased some wires, all the connections the rear of the Comanche and everything checked out fine, i read on another post that the NSS on the side of the trans can cause a blown fuse so i replaced it, now the fuse doesn't blow but i still have no reverse lights. i chased the wiring from the back of the jeep to right where the harness goes into the cab from underneath, i tested the harness and the brown feed wire for the reverse lights is staying grounded, if i put power to it the lights instantly come on. i tried to chase the wire into the cab but i can't seem to find it. I'm assuming whatever is the switch component for that brown wire isn't working probably but I'm not quite sure where it goes. If anyone has any idea or suggestions its greatly appreciated. and overall I'm just trying to avoid running a toggle switch for these lights but it definitely might come to that.

I had to do a little digging but I just found one by finding their website and cross referencing the part number. Thank you, I’ll post the link for it here for anyone that needs one in the future. https://www.justgastanks.com/comanche-mj-1987-1990-18-23-5-gal-f-i-w-pump-4-0l/

Reviving an old thread I’ve read pages and pages of trying to find a more recent answer. Most recent I saw was 2019. In the past 4 years has anyone discovered a way to get a new sending unit for these Comanches or have they only gotten harder to find? Mine currently has a band aid on it due to one of the 90’s getting a hairline crack right on base of the sender. I’d like to be able to replace it but that appears to be almost impossible, any advice helps! Thanks!

I wanted to revise the thread, I found a solution for my problem and my jeep has been fixed and running well for about 2 weeks now. I changed the electric fan for one out of a 97 much like someone had suggested, and it’s been running cool ever since. A/C on, sun coming down. The temp no longer goes above 210. And on cooler days it stays around 200 degrees constantly. I’m not 100% sure what the difference is as far as the fans other than a different blade design but boy does it move some air. I wanted to thank everyone for the advice on here and all the help because it had me absolutely stumped.

Yes, I have the OEM fan shroud, and yeah, once I’m moving the temperature regulates, it’s basically only at a complete stop or at an under 10mpg issue. It’ll run down the highway or on normal roads all day at 195-210

1. Yes it is an OEM type radiator 2. yes it is filled with 50/50 and clean water 3. the electric fan is working, and with the A/C running it practically never shuts off 4. the thermostat is functioning properly. I tested it before installing it 5. The fan clutch does seem to be functioning properly, spins freely when cold and locks up solid when warm 6. The condenser is clean 7. The hoses are nice and firm when cold, they were replaced in December 8. when the temperature takes off to the moon the coolant expansion tank looks swollen but doesn’t leak out. I try to shut off the jeep or get to a long stretch of highway as soon as it starts crawling up in temperature, but when I have check it when it’s hot the expansion tank is definitely swollen and when I shut the truck off it gurgles a bit.

The coolant that came out looked pretty clean, and I checked the gauge sending unit with an infrared thermometer, it reads accurate, I used the infrared on the elbow on the front of the engine when the truck runs real hot, and it’s reading about 230-240. Today it was cooler and I drove around all morning with little to no issues, it wasn’t until the temp climbed over a 100 did the truck start to overheat again.

Since you and I last talked I installed a new radiator and a new clutch fan, and it does have an electric fan. Yesterday it was about 108 degrees and after 10 minutes of sitting in traffic the temperature just started climbing rapidly.

Fan shroud is intact. Thermostat, coolant, clutch fan, and radiator all all brand new, water pump on a few months old, as off all of those repairs, it runs phenomenal until the temp of the day is about 100 degrees. Then it just keeps climbing.

I was the host of that thread. I’ve tried most things except an open cooling system.

I just moved out to Arizona, so the desert heat is definitely having some effects on the comanche. Just afraid of roasting the poor thing. The second I’m in traffic the gauge just starts creeping up and I’d really hate to blow the poor thing up.

Hello everyone, the running hot comanche is back again.( 1988 4.0 automatic transmission with 102k miles) So, I flushed the coolant, changed the thermostat, water pump is pretty new, radiator is brand new, gauge sending unit is about a month old. And yet the gauge runs got. I bought a infrared thermostat gun and I aimed it at the radiator, nice and cold at 185 Fahrenheit on the outlet, about 210 Fahrenheit on the inlet, yet the thermostat housing on the black read 230+. Houses were about 205-215 and the block on the passenger side was about 210-220 and the block near the manifold was nearly 300 degrees. Is this roughly normal. Or is this poor thing cooking. Thanks for any and all advice.

Goodmorning to the legend himself. I’ve already done this tip, as well as several others from your website, not all at once but over the last year and a half of owning the rig. I did the fuel pump ground 4-5 months ago and i checked it to make sure it was still good and solid ground during this whole debacle and it’s still good. At the moment the jumper wire bypassing the resistor seems to work. Doesn’t get warm to the touch or anything and well, I need to be able to drive the manche so for now it’s the fix I guess.

Radical. I kind of have no choice but to leave it for now and hope for the best. The jumper wire doesn’t get warm and it runs excellent with it jumped so. Idrk anymore

I’ve tried 2 different ballasts and ohm tested them before and after and they checked out. It just refuses to run if there’s a ballast resistor. I’m stumped. I even put a MSD resistor that was only 0.8 instead of 1.2 and it still wouldn’t stay running

Hello everyone, I’m going to try and be as thorough as possible because my jeep has me stumped. I have an 88 comanche. 4.0 auto trans that I’ve owned for the last 30k miles. Until recently it never missed a beat but I’ve done repairs since I’ve owned it. As of late it’ll intermittently just not run. Start. Run for 5 seconds and die. It has a brand new fuel pump, crank sensor is about 5 months old, I’ve tried the new and old ballast resistor, checked fuses, checked wiring, cleaned the C101 connector, ran some new grounds, changed the fuel pump ground as suggested by cruiser54s website. And the only way this truck will run is to bypass the ballast resistor with a jumper wire, then it runs fine. Does anyone have any suggestions of what it might be? Or should I just say screw it and leave the resistor bypassed.

I’m still wet behind the ears compared to yall but I appreciate the help immensely.

Hello everyone! I just moved from Mass to Arizona and my manche made the trip with relative ease, but now that I’m the desert I’ve noticed over the past week or so it’s running a little bit warmer than it ever has. I don’t have anywhere to do the work myself, as much as I’d prefer to so I was wondering if anyone could recommend a shop or a place where I could get a new radiator/ coolant flush. Preferably with my own parts.

New thread it is lol. Thanks!

Small world man, small world. Do you have an address for the Jeff’s auto? So I might be able to give them a try?

Worcester County area. Oxford MA

Just moved here from Mass, I did all my own repairs as well. Now I’m in Tempe AZ