pilecenturyfarm Posted April 15, 2012 Share Posted April 15, 2012 Hey guys... got an issue and I'm afraid I already know the answer buy am going to ask anyway. Had the Comanche for a week and love it. Been slowly working and replacing little stuff on it. Wired in the radio this morning... previous owner had pulled his radio out and half-assed wired in a cheap cassette player that didnt fit the hole, hooked to one speaker, and fell out when i accelerated hard. Got the new radio hard wired in and it didnt work. So went to my father-in-laws and parked it... I checked all the connections with a test light and have power figured out it was the radio. So my wife and father-in-law swapped the headlights and while they did that I was checking fuses and replacing what he had done... has some 20 amps in where 10s went and so on. Anyway box is loose and I also felt some fluid so know i have to change the clutch cylinder. Well went to start it and it would crank but I noticed the fuel pump didnt kick on. Checked all the fuses, then again, then tested everything we could. Got to looking under the hood and there are wires ziptied everywhere and cut. So started fixing what we could. Then noticed fuel pump resistor was cracked and ziptied back together so i cut that off and wired the two together with 25 amp fuse between them. Anyway thought it might be the pump. So dropped the tank and found where the guy had taken it offroad and not cleaned the mud and it was packed between the tank and skid so cleaned that up. Got the pump changed and everything back in and still nothing pump won't kick on. While checking the little stuff noticed that my headlights quit working and when I turn them on my interior lights and my cigar lighter quit working. Me and my father-in-law are pretty savvy but not much up on electrical. So sorry for all writing but wanted to cover everything. Anyone who can offer some suggestions please let me know... thanks guys I appreciate it. Link to comment Share on other sites More sharing options...
Jeep Driver Posted April 15, 2012 Share Posted April 15, 2012 Be afraid of what? Ain't skeerd of nothin. Link to comment Share on other sites More sharing options...
Jeep Driver Posted April 15, 2012 Share Posted April 15, 2012 Cruiser will be around with his electrical refresh instructions. Sound like your fuse box has had it with the brake master leak. Grounds and cables and connections and sensors are important here. Cruiser's write-ups are here. http://jeepseekers.com/cruisers_writeups_65.html Link to comment Share on other sites More sharing options...
pilecenturyfarm Posted April 15, 2012 Author Share Posted April 15, 2012 thanks... ill check out his site Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 15, 2012 Share Posted April 15, 2012 Do you have diagrams (they're in the FSM and some of the aftermarket manuals)? And do you know how to read them? I'd start by taking contact cleaner to the fuse box. Try to flush the brake fluid out of it, then take a good strong light and look it over well. If the fuse contacts are all corroded, and the plastic is failing, then it's probably too late for the box... Not a good thing. Beyond that, just start tracing wires on the systems that don't work. Watch for the common grounds, they cause more grief than most people realize. And I'd take apart all connectors and clean them out with contact cleaner, inspect them, then reapply dielectric grease to them to prevent corrosion. If you get a GM pin tool you can reseat any loose pins in the connectors, or pull them apart to clean off corrosion as needed; Lisle tools makes some universal pin tools that aren't too expensive. Link to comment Share on other sites More sharing options...
cruiser54 Posted April 15, 2012 Share Posted April 15, 2012 thanks... ill check out his site Actually, it's Murphy's site but feel free to check it out. He's posting all my write-ups there. If I were you, I would do the Ground Refreshing and Relay/Connector refreshing right off the bat. I'll provide them here for you. What year is your Comanche BTW? Renix Ground Refreshing The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, and wasted money replacing unnecessary components. The components grounding at the dipstick tube stud are: Distributor Sync Sensor, TCU main ground, TCU “Shift Point Logic”, Ignition control Module, Injectors, ECU main ground which other engine sensors ground through, Oxygen sensor, Knock Sensor, Cruise Control, and Transmission Sync signal. All extremely important stuff. The factory was aware of the issues with this ground point and addressed it by suggesting the following: Remove the nut holding the wire terminals to the stud. Verify that the stud is indeed tightened securely into the block. Scrape any and all paint from the stud’s mounting surface where the wires will attach. Must be clean, shiny and free of any oil, grease, or paint. Inspect the wire terminals. Check to see that none of the terminals are crimped over wire insulation instead of bare wire. Be sure the crimps are tight. It wouldn’t hurt to re-crimp them just as a matter of course. Sand and polish the wire terminals until clean and shiny on both sides. Reinstall all the wires to the stud and tighten the nut down securely. While you’re in that general area, locate the battery negative cable which is fastened to the engine block just forward of the dipstick stud. Remove the bolt, scrape the block to bare metal, clean and polish the cable terminal, and reattach securely. Another area where the grounding system on Renix era Jeeps was lacking is the engine to chassis ground. There is a braided cable from the back of the cylinder head that also attaches to the driver’s side of the firewall. This cable is undersized for it’s intended use and subject to corrosion and poor connections at each end. First off, remove the cable end from the firewall using a 15mm wrench or socket. Scrape the paint off down to bare metal and clean the wire terminal. Reattach securely. Remove the other end of the cable from the rear of the head using a 3’4” socket. Clean all the oil, paint and crud from the stud. Clean the wire terminal of the cable and reattach securely. A suggestion regarding the braided cable: I prefer to add a #4 Gauge cable from the firewall to a bolt on the rear of the intake manifold, either to a heat shield bolt or fuel rail bolt. A cable about 18” long with a 3/8” lug on each end works great and you can get one at any parts store already made up. Napa has them as part number 781116. A further improvement to the grounding system can be made using a #4 cable, about 10” long with 3/8” terminals at each end. Attach one end of this cable to the negative battery bolt and the other end under the closest 10mm headed bolt on the radiator support just forward of the battery. Napa part number 781115. If you want to upgrade your grounds and battery cables in general, contact Jon at www.kelleyswip.com. He makes an incredible cable upgrade for a very reasonable price. Revised 11-28-2011 I suggest unplugging EVERY electrical connection in the engine bay you can find, whether engine related or not, and spraying it out with a good electronics cleaner, visually inspecting the terminals, and adding dielectric grease before plugging it back together. Be sure that the connectors to the ballast resistor mounted near the air cleaner housing are clean and tight. ALL of the relays should be removed, the terminals wire-brushed until shiny, and the receptacles sprayed out with contact cleaner. Then dielectric grease should be added before plugging them back in. I do this on every Renix era Jeep I purchase or work on for someone else. Revised 03/15/2012 Link to comment Share on other sites More sharing options...
cruiser54 Posted April 15, 2012 Share Posted April 15, 2012 thanks... ill check out his site Actually, it's Murphy's site but feel free to check it out. He's posting all my write-ups there. If I were you, I would do the Ground Refreshing and Relay/Connector refreshing right off the bat. I'll provide them here for you. What year is your Comanche BTW? Renix Ground Refreshing The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, and wasted money replacing unnecessary components. The components grounding at the dipstick tube stud are: Distributor Sync Sensor, TCU main ground, TCU “Shift Point Logic”, Ignition control Module, Injectors, ECU main ground which other engine sensors ground through, Oxygen sensor, Knock Sensor, Cruise Control, and Transmission Sync signal. All extremely important stuff. The factory was aware of the issues with this ground point and addressed it by suggesting the following: Remove the nut holding the wire terminals to the stud. Verify that the stud is indeed tightened securely into the block. Scrape any and all paint from the stud’s mounting surface where the wires will attach. Must be clean, shiny and free of any oil, grease, or paint. Inspect the wire terminals. Check to see that none of the terminals are crimped over wire insulation instead of bare wire. Be sure the crimps are tight. It wouldn’t hurt to re-crimp them just as a matter of course. Sand and polish the wire terminals until clean and shiny on both sides. Reinstall all the wires to the stud and tighten the nut down securely. While you’re in that general area, locate the battery negative cable which is fastened to the engine block just forward of the dipstick stud. Remove the bolt, scrape the block to bare metal, clean and polish the cable terminal, and reattach securely. Another area where the grounding system on Renix era Jeeps was lacking is the engine to chassis ground. There is a braided cable from the back of the cylinder head that also attaches to the driver’s side of the firewall. This cable is undersized for it’s intended use and subject to corrosion and poor connections at each end. First off, remove the cable end from the firewall using a 15mm wrench or socket. Scrape the paint off down to bare metal and clean the wire terminal. Reattach securely. Remove the other end of the cable from the rear of the head using a 3’4” socket. Clean all the oil, paint and crud from the stud. Clean the wire terminal of the cable and reattach securely. A suggestion regarding the braided cable: I prefer to add a #4 Gauge cable from the firewall to a bolt on the rear of the intake manifold, either to a heat shield bolt or fuel rail bolt. A cable about 18” long with a 3/8” lug on each end works great and you can get one at any parts store already made up. Napa has them as part number 781116. A further improvement to the grounding system can be made using a #4 cable, about 10” long with 3/8” terminals at each end. Attach one end of this cable to the negative battery bolt and the other end under the closest 10mm headed bolt on the radiator support just forward of the battery. Napa part number 781115. If you want to upgrade your grounds and battery cables in general, contact Jon at www.kelleyswip.com. He makes an incredible cable upgrade for a very reasonable price. Revised 11-28-2011 I suggest unplugging EVERY electrical connection in the engine bay you can find, whether engine related or not, and spraying it out with a good electronics cleaner, visually inspecting the terminals, and adding dielectric grease before plugging it back together. Be sure that the connectors to the ballast resistor mounted near the air cleaner housing are clean and tight. ALL of the relays should be removed, the terminals wire-brushed until shiny, and the receptacles sprayed out with contact cleaner. Then dielectric grease should be added before plugging them back in. I do this on every Renix era Jeep I purchase or work on for someone else. Revised 03/15/2012 Link to comment Share on other sites More sharing options...
pilecenturyfarm Posted April 15, 2012 Author Share Posted April 15, 2012 Thanks for the help guys. I'll pull the fuse block this afternoon. Truck is an 88 4x4 5spd. Rust free but po replaced the engine and I'm finding he did a pretty cruddy job. Link to comment Share on other sites More sharing options...
cruiser54 Posted April 15, 2012 Share Posted April 15, 2012 double post Link to comment Share on other sites More sharing options...
cruiser54 Posted April 15, 2012 Share Posted April 15, 2012 quadruple post Link to comment Share on other sites More sharing options...
cruiser54 Posted April 15, 2012 Share Posted April 15, 2012 triple post Link to comment Share on other sites More sharing options...
cruiser54 Posted April 15, 2012 Share Posted April 15, 2012 Since you have an 88: Renix Jeep C101 Connector Refreshing The C101 connector on 1987 and 1988 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and increased resistance over a period of almost 25 years. The C101 connector needs to be cleaned at least once in the lifetime of your vehicle. Chances are it’s never been done before. Almost every critical signal between the engine sensors, injectors, and the ECU travel the path through the C101. The C101 is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time. Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth. If you have a small pick or dental tool tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter. Apply a true dielectric grease, not the stuff that came with your brake pads, to the connection and bolt it back together. Revised 11-29-2011 Link to comment Share on other sites More sharing options...
pilecenturyfarm Posted April 16, 2012 Author Share Posted April 16, 2012 so just thought i would give an update after spending all weekend working on it and still nothing. event tried hooking the fuel pump directly to the battery through the ballast and still nothing. .... gonna try cruisers stuff on cleaning connectors and grounds this afternoon if it doesnt pour the rain here. also got the fuse block pulled apart and all it was full of looked like old dielectric grease. so thinking the cylinder isnt leaking but connectors are pretty corroded. gonna look at doing a swap but have to get it running to get it home first so well see. thanks again guys for all the help. Link to comment Share on other sites More sharing options...
pilecenturyfarm Posted April 16, 2012 Author Share Posted April 16, 2012 ok... so i was talking to one of the teachers i work with and he just redid an 89 cherokee... he said his fuel pump quit when he tore his carpet out because he cut the wire that powers the fuel pump. the po of mine had run sub lines for an amp along the door and i jerked those out when i was working on the radio and may have inadverntley damaged the wire... gonna pull the carpet this afternoon and check that and put the fuse block back together... hopefully that will fix the problem :thwak: Link to comment Share on other sites More sharing options...
pilecenturyfarm Posted April 17, 2012 Author Share Posted April 17, 2012 so no luck.. now when i turn on my headlight switch lights don't come on, temp gauge starts spinning and the shift, park brake, and seat belt light kick... i think i might have a short somewhere...lol. gonna take it and have an electrical guy trace and let him look at it Link to comment Share on other sites More sharing options...
cruiser54 Posted April 17, 2012 Share Posted April 17, 2012 I'd try this first: Improving the Instrument Panel Ground The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼” or 5/16” head on it. This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things. The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple. Make up a jumper wire with #10 gauge wire about 10” long. On one end, crimp on a ¼” round wire terminal. On the other end, crimp on a 3/8” round wire terminal. Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other. Look above the driver’s side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely. **Special note for Comanche owners: Make your jumper wire 12” long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.** Revised 11-29-2011 Link to comment Share on other sites More sharing options...
mvusse Posted April 17, 2012 Share Posted April 17, 2012 If it's really as badly hacked up as it sounds I would start with replacing the entire engine bay and dash harnesses. They are easy to find in a junkyard as Cherokees used the same ones. Also, the fuel pump grounds by the driver side (or was it passenger?) tail light. Check that out. Link to comment Share on other sites More sharing options...
cruiser54 Posted April 17, 2012 Share Posted April 17, 2012 Driver's side. Link to comment Share on other sites More sharing options...
pilecenturyfarm Posted April 17, 2012 Author Share Posted April 17, 2012 ive just about come to the end of it... thinking about just selling it the way it sits for a project... but the shop teacher here where i work is really good and loves electrical systems so I'm hoping he can fix it. if not then ill start looking at a new harness... did pull up a corner of the carpet so ive got a little rust to deal with too.. but gonna tackle the electical first Link to comment Share on other sites More sharing options...
HKB3 Posted April 21, 2012 Share Posted April 21, 2012 I know this may sound out of line but are you sure the fuel pump works? I went through a similar thing with a mustang when I first started driving after going over anything and everything it turned out the fuel pump just quit. :doh: Link to comment Share on other sites More sharing options...
Jeep Driver Posted April 21, 2012 Share Posted April 21, 2012 I'm not too far from ya............how much you want for it? Link to comment Share on other sites More sharing options...
pilecenturyfarm Posted June 28, 2012 Author Share Posted June 28, 2012 so haven't posted in forever... finally getting my comanche back at the end of the week.. whole problem with the electrical system was the computer got fried... got a new one and it fired right up. my buddy is finishing up a few things. next up will be some floor fixing, radio, then a complete fluid change Link to comment Share on other sites More sharing options...
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