CAM997

First of all, I knew nothing about working on a vehicle until I got an XJ and found this forum. It's been super helpful and I've learned a lot. Thanks for that.

I have a 1998 XJ... I recently installed an ARB wiring harness, IPF H4 housings w/ 100/80 hellas and some KC Daylighters. I was having no issues prior to these installs. I started with H4's on the old wiring harness, just to test them. They worked and I didn't notice any issues. I then installed the wiring harness with the H4's. I guess I plugged the new harness into the old harness through the wrong headlight plug. I initially plugged it into the driver side headlight plug and the driver side low beam would not come on, but passenger did, both high beams worked. I then noticed the check guages light on and the voltage was down to like 9v on the guage in accessory mode. I switched the ARB harness around and plugged it into the old wiring harness through the passenger side and the headlights worked, no more check guages light, and voltage was hovering around 12v in accessory mode. I figured everything was good to go at that point with that, so I disconnected it all and installed my KC Daylighters. Everything seemed fine with that setup, lights came on, no check guages light, 12v in accessory mode. I then reconnected the ARB harness w H4's and daylighters at the same time, and everything got funky. I put it in accessory mode and was getting 12v with no check guages light, I thought everything was good to go. But when I tried to start up it wouldn't. I don't remember exactly what happened with the cranking that time, but I think it cranked but weakly and then the voltage dropped back down to like 9v and the check guages light came on. I disconnected all of the new stuff. But the low voltage, check guages, and issues starting persisted. I charged my Interstate AGM battery overnight (MTZ-34), no more check guages when i reconnected the battery, voltage back to ~12v in accessory mode. Trying to start, it struggled to crank, sputtered, but started up. I tried again a few hours later and it started up kinda slow but fairly normal. The next day I turned the key and nothing. Tried again a while later and it cranked weakly on first try for a second then stopped. Cranked a little more on second try but no start. Then cranked stronger on 3rd try, sputtered but started. I took my battery to interstate, they said it was giving 12.3v but should be about 12.7v. They charged it then tested it. Their test shows the battery is good, has about 694 CCA, its a 800 CCA battery. Autozone test said the battery is bad, cranking health passed, but reserve capacity was poor. I just reinstalled it and tried again (none of the new light setup connected), basically the same thing happened that did after I charged it myself. I read 12.8v coming from battery before install, then installed and in accessory mode it was showing above 12v on guage, no check guages light. Then trying to start it... Nothing on first attempt. A weak one second crank with no start on second attempt. A couple more seconds of weak cranking on third attempt. Then more cranking on 4th attempt, sputtering, then started. Everything seems fine when running, voltage reads right about 14v when running. The check guages light comes on when trying to start but goes away after startup. Check engine light comes on during sputtering, but goes away after startup. I cleaned all of my grounds just in case.

Checking the forum I don't find anything similar to this. I appreciate any ideas or suggestions on what I should check and do. Do you think maybe I messed something up electrically with the installation, possibly when I installed the ARB harness into the old harness on the drivers side, when I first noticed the check guages light?

CAM997

Additional info: I checked the voltage at the starter and its reading ~12.5, which is almost identical to what the battery is at the moment. The voltage at the alternator is ~10.8v though.

That Jeep Guy XJMJ

condition of battery terminals? lose ground from the Neg. battery terminal to body?

CAM997

It looks like it's going to be the clutch starter switch. This video by Bleepinjeep helped me in diagnosing the problem. I just substituted the possibility of the neutral safety switch with the clutch starter switch (I have a manual). I was fishing the KC wires in through the grommet that the hood release cable runs through, and must have done something to the switch while my hand was moving it around. I found info on bypassing the switch (in my case there was something taped to it that you remove the switch plug and plug that piece into it). It's been starting up with no issues at all for several days with the switch bypassed. I will confirm if this was the long term answer down the line if everything continues running smooth, in case it's helpful for anyone else. Thanks for the reply.