charging problem

[rrbtheman]

ok i have been having a problem ever time it rains and i have everything on the voltage would get low but if i turn it off and restart it the votage goes back to normal until about 5 mins late and not to long ago i went thorugh a bit puddle and the voltage went like into the red so i replaced the altenator 3 time but i am still having the same problem is there a relay for it or what cause i am stuck

[GTP Dad]

I would check the belt. It may be going bad even though you don't hear squealing. It sounds like it is slipping and when the van warms up the belt warms up too and the alternator starts charging again. This would also be indicated by the fact that the voltage drops when you go through a water puddle.

[yogi_123rd]

I experienced very simular symptons on my 88 Caravan. Each time it rained, or got misty out, the alternator would stop charging. It was not the belt nor the alternator. Water was shorting something out.
It is my understanding that alternators regulate voltage with crystal diodes in the alternator unit itself. I suspect the ECM or BCM is somehow involved with a control circuit of some kind for regulating voltage.

The would be a good question (what components regulate voltage) to ask the board to anybody with an in depth knowledge of Chysler charging systems.

I can only offer my unconfirmed suspitions that the ECM is somehow involved in regulating the charging circuit. This would be a good question to ask the board.

[rrbtheman]

so you saying it could be a part called the emc?

[gforster]

Yes the pcm is definately responsible for the charging voltage regulation. I have seen this fail many times. What you can do is replace the ecm from one in the junkyard with the same model year and options/engine, or you can purchase an older style chrysler external voltage regulator and wiring pigtail, cut the green wire going from alternator to ecm, and wire the alternator side of it to the control terminal on the regulator. Connect the other terminal to the ignition circuit (hot in run only) and make sure the regulator is snugly mounted to sheet metal for a good ground (use star washers) I've done this many times and it works like a charm. You can email me directly at [email protected]

[rrbtheman]

i have a older model van it a 1989 voyager 2.5 l