My son has an 89 XJ, 4.0 that he just picked up a couple weeks ago to mess around with. When he got it it ran fine. Last week he said the voltage meter was reading 9 volts. He replaced the alternator thinking that was the issue. It still is reading 9 volts. If he turns the lights on the voltage drops even further. Any ideas of where he should start looking? Grounds maybe. Anything standard after that?

Sorry for the basic questions but I am not a mechanic by any stretch of the imagination.

 

Greg: click on the link in my signature and do Tips 1,3,4, and 5,

 

Also after cruiser fix theres these...http://www.jeepforum.com/forum/f11/r...ge-fix-684375/


https://www.cherokeeforum.com/f2/vol...0-cost-177985/

 

Thanks for the help. We haven't had time to do anything yet but I'll give an update in a couple days. Hopefully it is short and simple

 

Slow going so far mostly from weather and lack of time. First of the alternator was replaced, whether it was needed or not, before we started the checks. I replaced some (ok ... a lot !!) hacked up wiring the PO had done. It was obvious that he found a very good sale price somewhere on electrical tape.

Anyway, the voltage at the battery when off is a little over 12 and over 14 when running. We refreshed all ground points. I have ordered the 2 additional ground cables recommended by Cruiser. One item we found was the PO had connected the neg battery cable to the dipstick bolt. So if anyone knows off the top of their head what bolt size to use to connect the neg batt cable to it's proper place on the block, it sure would be appreciated.

All electrical connectors have been refreshed/cleaned and reconnected. The coil was removed, connectors cleaned and the coil re-seated again.

My son also replaced all the spark plugs (they needed replacing) and the plug wires. One thing I did find was the distributor could be rotated easily by hand. So we reset the timing and tightened down the distributor housing.

I will check the sensor grounding this evening. Right now the jeep fires right up and seems to run fine. The battery gauge is still showing low so we will be making the fix recommended by Freegdr in the near future.

That's it so far.

 

Way to go!!!!!!

It's a 3/8-16 bolt IIRC.
See Tip 13 to be sure you got the "timing" set correctly if you haven't already.