Ok, I've posted before. Have 2 GCs, like them and do all work on them. So I am fairly familiar with working on them.

Problem with Wife's 97 (3.8L SE) (so I am in hot water).

She started complaining ~ a month ago that the car would not start in the first 2-3 attempts. "sounds like it's not even turning over". I tried it and it was fine. No symptoms whatsoever.

A couple of weeks later: she calls me that the car seemed dead and she had to get someone to give her a jump at work. She gets home and I see nothing wrong. No codes. Battery checks out. Alternator checks out. Drive was only 20 mins home and battery shows full!

A few days go by. She complains that twice the same day the car would not start and she had to be jumped. "When I turn the key all I hear is clicking and that's it". She gets home I check and somehow the negative terminal on the battery is fairly loose. I tighten it up and everything looks fine. I am left to think that was the issue.

This past Saturday. We drive downtown to a museum. I am driving back. Suddenly about 15 mins into the drive the battery light comes on. "Alternator" I think to myself. 3 mins later lights start flashing and there is a loud clicking sound from the engine compartment. Sounds like from the fuse box (drivers side, right behind the firewall). I pull on the side of the highway and the car dies. Battery appears to be pretty low, can hardly play the radio!!

Luckily, someone stops 5 mins later and jumps us (yes, we've been very lucky). We drive home with no issues. The battery light does NOT come on at all. I take the battery and alternator off and take them to 2 separate auto stores to be tested. They both pass with flying colors!!! 2 stores, 6 tests each!!

An electrical short? It's been so freaking cold here in Chicagoland the last month, I can't really stand more than 30 mins in the garage without loosing feeling in my extremities so I can not do that much. I clean up all terminals to the alternator & the battery, hook everything back up. Car fires up immediately and seems to have no issues.

Today, 5 days later. Wife calls that the car died on her on the way home. She says the battery light came on again this morning but the car drove fine. Started fine on the parking lot of her job but 10 mins into the drive, lights went all crazy in the car, the windshield wipers came on, the lights on the dash were going up and down. She just managed to pull to the side when the car died.

I drive to her this time. I disconnect the battery, reconnect it and I jump the car. Fires right up. I drive it on the way back and for 20 mins it drives with no issues. As I am about to pull on the driveway, battery light comes on again - no other side effects.

So, what do you all think? Sounds like an electrical short/leak? Any fuses I should check? The situation seems to be alleviated when the battery gets disconnected from the car but it comes up at a later time anyway.

I am banging my head against the wall here. If it was a fuse, then the issue would be there all the time, right? A fuse is blown or not - there is no between stage. PCM maybe?

Car has 198,000 miles and we were just talking about how nice it's done overall through the years. Other than a few small things here and there and a rebuild tranny ~ 150K miles, it's been very good to us. No rust, looks quite nice and drives nicely and all until this happened.

ANY ideas would be greatly appreciated. What the heck do I check? What fuse/connector could possibly interfere with the Alternator circuit?

It has been VERY cold the last month or so here in Chicagoland but the battery is just a year old and it passed every test thrown at it with flying colors. Same with the alternator!

 

SOunds like you have a bad ground somewhere.

 

I've been reading up on this and apparently the Voltage Regulators in these vehicles is in the PCM?

Can anyone confirm that? Could this be the culprit here? I've though about a ground somewhere in the system but how come it works fine for days in a row and then comes back? From all the time that I spent taking the alternator & battery in & out, I did not see any cables in dissaray or loose or anything.

Of course it could be one of the fusable links in the harness but wouldn't the car display the same behavior all the time?

 

I have an '06 T&C, it would stall when put into reverse, but not every time, sometimes I would get the CEL and a code, sometimes not.. The codes were erratic from egr to cam sensor, o2 sensor, crank sensor and so on... I had a difficult time duplicating the problem, and it would come and go randomly. It finally got to me when it started to do it when accelerating, it would sputter and surge. I checked and replaced everything i got a code for, and the problem would go away for a while, then come back. I was eventually able to trace it ti a bad ground in the wiring harness. Some rocket scientist at Chrysler feels that hotglue and shrinkwrap makes for a comparable connection to actually soldering the wires together. This was definately a factory joint, because I had to remove the part # tag and factory tape to get to the problem. I suggest you start the car and try shaking the harness "vigorously" and see if you can duplicate the problem. If yes start looking at the blue ground wires in the harness for failed splice connections.

 

Wow, that's the one thing I did not want to hear about. Having to find a blown fusable link is not exactly my idea of fun plus you can never be exactly certain.

Before I tackle this, I was thinking about bypassing the PCM Voltage Regulator to rule that out first. I've read references online to that but no more specific info.

Anyone knows how to do that? Or has a relative link?

 

Update:

local dealer 1 says that they cannot bench test the PCM. They have to test it on the vehicle for ~ 1 hour. Cost: $137.50

local dealer 2 says that although the test the PCM on the vehicle, they will not be able to tell about the Voltage Regulator. I would need to find a shop that refurbishes them and they can test it out.

eBay has a couple of companies that sell PCMs for this GC for $100 incl programing which is an exceptional price in my book. Question is, do I need one?

Took it to the local auto store to have codes read (in case there were any while wife was driving). Car had the battery light indicator on all the way there. Guy plugged in the scanner, got no codes. Restarted the car and for 5 minutes the light was off! It came back on as I was pulling on the driveway.

Which leads me to believe this might be a relay issue? Relays of course reset themselves so hooking up the scanner could have accomplished that. It could also point even harder to the Voltage Regulator on the PCM (since it was accessed during the test).

Hmmmm. The wiring diagram says that there are 2 relays (Engine Starter Motor + Automatic Shut Down) & 2 fuses in the PDC involved as well as 1x Fuse in the Junction Block and of course the fuseible link from the alternator involved in the charging system.

Time to start testing fuses and pulling relays methinks..... I hate electrical problems!

 

Here's what I found....
In the first pic you can see the blue wire in the center just hanging there, it simply fell out of the splice when I pulled the harness cover off.

 

Checked the harness, checked the relays, checked the fuses. All check out with no problems. Car is consistently not charging the battery at all for the last 4 days.

Only thing I have not checked yet is the fuseible link that goes to the alternator (cause I need to take everything apart again!). I think I'll swap out the alternator anyway since the car just hit 200,000 miles so it cannot be that long before it goes. And it could actually be the reason for the issue - although it tested fine multiple times. I'll check the fuseible link at the same time too of course IF I can figure out how to get to it seeing as it runs all the way behind that big a$$ intake plenum!

With the new alternator & a checked fuseible link, it would only leave the Voltage Regulator in the PCM unchecked and the possible culprit. I just wish I had something a little more firm as I HATE just throwing parts at issues but I need the car running properly again!

If anyone has any other ideas/suggestions, they would be much appreciated.

 

If you have a volt meter, First few things i would check....
Drop your meter onto the terminals and see what the alternator is putting out for Voltage. Then put one connector on the positive terminal, and one on the Alternator make sure the voltage is the same. Then move your connector too the positive batt terminal, and the other connector too the car frame. Again make sure your voltages are correct.

Then switch your volt meter too check Resistance.
go from the Positive Battery Terminal, too the positive battery cable Clamp make sure there is no resistance... Do the same for the Negitive Post too clamp. if you have more than an ohm of resistance, hints at a bad connection, tighten up the clams.

Check from the alternator too the negative post for resistance, again make sure there is *******ly no resistance.

What this is doing is checking for bad connections. Resistance shows weather the connection is a good one or a bad one, the more resistance the worse the connection is. Why would this be an issue? Because even if the alternator is putting out 14.5v like it should be, it might not be putting the Amps it needs too charge the battery.

Also check your grounds... There are Three grounds in the engine compartment that i can think of... One from the Battery too the Engine. Then 2 mess wire that are notorious for rotting out. One is located at the back of the engine too the Firewall. and the other one that i know about is on the right side of the engine, and it goes from the Top of the engine mount, too the bottom of the engine mount. Make sure these grounds are okay, Another way too test if you have bad ground issues... Take a pair of jumper cables take one clamp, and clamp it down on the negative terminal, and take the other side of it, and clamp it down too the Body making sure your not clamping down on Painted metal. Move it too verious parts of the body too test it.

As for a new PCM, I picked up a PCM from my local junk yard for 50$ If your gonna junk yard crawl for a new PCM, make sure you get the same year range, and Features.
for example if you have a 94 caravan with a 3.0L 3 Speed with AC you need too pull another pcm out of a 3.0L 3 Speed with AC. usually you need need too find the exact year for replacement, just year range and with the same features like AC / Tranny speed.