Few electrical questions

[azdesertrhino]

I've read as many posts as I can find regarding charging problems but still have a few questions.

94 XJ 4.0 - Not charging battery. Had generator bench tested. Checks out with same numbers as a new one.

Tried a new battery. Voltage drops when I start engine and continues to drop. Battery voltage recovers after engine is shut off.

Checked and cleaned all grounds, connections, terminal etc.

1) I read there are fuses in the PCM. I don't see anything in the FSM regarding fuses actually located in the PCM but do see fuses referenced for the generator in the power distribution module. Are these the fuses being referred to?

2) Regarding reading the voltage at the terminals on the back of the generator? Can someone explain the actual readings between the different terminals.

3) Is there a way, as a test, to bypass the PCM voltage regulator before I buy a new PCM.

Any other pertinent information would be greatly appreciated.

[outlander]

Check your battery cables for corrosion?

[langer1]

Is there a way, as a test, to bypass the PCM voltage regulator before I buy a new PCM.

Well you pretty much did that when you bench test the unit.
What about the Fuseable link?
I think a bad Ignition switch is a also possibilty.

[azdesertrhino]

I didn't realize the ignition switch could keep the thing from charging the battery. Could you explain a little further?

[XJING]

I have to go simple on this one. Why dont you get a heavier guage wire and run it from the altenator back to the distribution center. Seems you might just have a bad wire and are over diagnosing it. Here is a page that might help too. Good Luck
http://www.olypen.com/craigh/elec_system.htm

[old_man]

Clean your battery cables, both ends, especially where it contacts the block. Clean the connectors where they bolt together on the starter solenoid by the battery. Check for corrosion on the connection to the alternator. Use an ohmmeter and check that the cable from the alternator to the starter solenoid is intact.