chopper35nj Posted October 11, 2012 Share Posted October 11, 2012 Brakes sorted....I think. Engine running perfectly, New exhaust installed, sounds great. The next on my to do list was the head lights and turn/marker lights. The truck was a plow rig and had had the wiring bastardised by the previous owner. Removed the inline conectors re-soldered all the wires and shrink wraped them, done. Then I seperated the 10 pin connector from the wiring loom to the lights in the header panel. The conector was corroded beyond repair so I cut off the conectors and installed jacketed spade terminals on the six wires that run the front lights. In the conector attached to the main wiring harness there is a heavy gauge red wire that is a constant hot and a light green w/black stripe wire, they both apeared to terminate in that plug, there were no wires in the the recieving connector for them to go to. I fugured the constant hot was for fog lights and acording to my Haynes manuel seems to confirm that and I can't find anywhere in the schematic a light green w/black stripe in the front lighting system....so I clipped and capped them. So......here's the problem, since doing this the engine won't run, it labors to start races when it does and as soon as the engine builds vaccum it dies. WHAT THE HELL DID I DO? HELP!!!!! Thanx Eric Link to comment Share on other sites More sharing options...
chopper35nj Posted October 11, 2012 Author Share Posted October 11, 2012 Never mind......... bad conector on the funky lil resister next to the EGR solinoid. Thanks for looking. Eric Link to comment Share on other sites More sharing options...
cruiser54 Posted October 11, 2012 Share Posted October 11, 2012 What year MJ? Upon seeing your first encounter with the wiring, I would suggest doing this: 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 making sure they haven’t retracted into the plastic holder, and then plugging it back together. There’s a critical 10-pin connector for the front lighting system located in front of the air cleaner and behind the left headlight assembly. Don’t miss that one. Also 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 plug them back in. I do this on every Renix Jeep I purchase or work on for someone else. Revised 07/23/2012 Link to comment Share on other sites More sharing options...
chopper35nj Posted October 12, 2012 Author Share Posted October 12, 2012 Funny I should notice this now. I just spent the whole day doing just what you suggested, plus diaelectric grease on all connectors. That 10 pin connector that you mentioned is the one that I removed, it was too badly corroded to save and my running problem was the ballast resister, I replaced the terminals...no more problem. Thanks for the input, good advise. Eric Link to comment Share on other sites More sharing options...
cruiser54 Posted October 12, 2012 Share Posted October 12, 2012 Do this while you're at it then. LOL. 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 Link to comment Share on other sites More sharing options...
chopper35nj Posted October 13, 2012 Author Share Posted October 13, 2012 Hey Cruiser, I think we are on the same page. I just replaced all of the ground cables with battery ground cables from the part store. My braided cable was corroded badly, just made sense. Thanx Eric Link to comment Share on other sites More sharing options...
cruiser54 Posted October 13, 2012 Share Posted October 13, 2012 Hey Cruiser, I think we are on the same page. I just replaced all of the ground cables with battery ground cables from the part store. My braided cable was corroded badly, just made sense. Thanx Eric Never hurts and can only help. Did you do the refreshing though? Link to comment Share on other sites More sharing options...
Kona Posted October 14, 2012 Share Posted October 14, 2012 Could this be also a reason for the TCU not to work? Shoot ! I'll do this anyways! Great post! Link to comment Share on other sites More sharing options...
cruiser54 Posted October 14, 2012 Share Posted October 14, 2012 In the write-up, read what it says about what grounds where and you'll answer your own question. Link to comment Share on other sites More sharing options...
Kona Posted October 15, 2012 Share Posted October 15, 2012 Not to hijack but got all that done and upgraded cable and didn't fix the TCU problem, guess TCU it's really fried!, but at lest its done! Link to comment Share on other sites More sharing options...
cruiser54 Posted October 15, 2012 Share Posted October 15, 2012 Never hurts and frequentl helps. Link to comment Share on other sites More sharing options...
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