Hi Everyone. I'm about to crank up this 95 ZJ 5.2L. As near as I can tell, I have lost ground to all my sensors [tps, crankps, camps] that should have 5.0 volts to operate properly. When I test them for voltage, I get crazy readings like 15 volts. This makes me think my ground is weak. Knowing all this, where do I look to repair the old ground or create a new one to fix this problem. Its the pcm outgoing ground right? Where can i find that ground wire among the thousand coming to and from the pcm? Thanks

 

Welcome to the forum.

Disconnect the battery negative terminal, then disassemble, inspect and clean every battery positive and negative feed, on the body, the engine block and the alternator.

There are body connections near the battery. The engine block connections are down low. The alternator connections are at the rear.

 

I should have searched more before i posted. I apologize. I appreciate all that make this forum happen. Thank you!!

 

I will try that. I didnt realizeCruiser54 write ups were all about XJ's. They probably dont apply to a 95 ZJ would they? So Im back to needed more advice. So I'll start checking these grounds as suggested. Thanks

 

I have a 95 ZJ with a 4.0L that I'm slowing becoming more failure with.

I suggest first check the battery and alternator grounds and then around the engine - firewall, dipstick and coil. There are other ground points throughout the ZJ. I also have a 98 XJ that I've owned for over 10 years.

Below are some diagrams, schematics that show grounds for a 95 ZJ.

First schematic is 5.2l COMPUTER DATA LINES, next two are wiring diagrams of 95 ZJ ground and the last is all the Gxxx ground points. If you click on any of the diagrams they will enlarged.

I think I may also have a schematic of the 5 volts system or at least some related information. I haven't owned the ZJ very long and will need to look through it's FSM and paper factory manuals.

I found some good schematics better than the FSMs, from an online Mitchell manual and a month's subscription which I no longer have. It's something like $20.00 per month or you can subscribe for longer periods at a reduced rate.

https://eautorepair.net/Marketing/Default.asp
https://eautorepair.net/app/Model.as...&MKN=Jeep&PS=8

 

XJ, ZJ, WJ, any Jeep product, extra grounds cannot hurt.
On my XJ I have combination battery, top and side posts, I run separate grounds from each.
Buy premade and terminated ground wires at your local parts store, various lengths available.
XJ ZJ, and WJ, additional ground wires, batter to alt mount, firewall to block, etc.
Plus clean up your stock grounds.
My WJ seems particular sensitive to good ground at Battery.