DieRache

I have searched the site and have not found a good answer. I have a 94 zj inline 6. I just replaced the battery with a red top optima. The alternator is only 6 months old (new not rebuilt from auto zone). I have cleaned all grounds and checked all wires and replaced battery terminals.
When it is cold below 40 the voltage meter reads right at the 14 line. When Jeep warms up or temp is above 40 it starts at 14 and begins to drop and goes down to the line right under the 14 mark, side question what does that line represent 13 or 12? When I put it in reverse it goes down below that line. With a voltmeter at battery and everything on I get between 12.7 and 13.6 at idle.
I have had Alt tested at auto zone (in jeep) and they say it is good. After researching I see that there may be a battery temp sensor that may control the amount of charge going to battery. Question is does the 94 ZJ have one and if so where the heck is it?
Could this be a PCM issue and how do you test for that? This is driving me crazy. This is the 3rd Alt I have in 18 months. When I put in a new one seem to fix issue for awhile then it comes back. Any help on this would be great.

Turbo X_J

When is the last time the battery cables were checked for resistance/replaced?

Elec stuff
http://www.kelleyswip.com/

Fred/N0AZZ

Just under the 14 usually shows 13.8 volts in most cars when checked with VOM.


Do check out the above link supplied.