Hey all,
Well, I'm back again looking for advice...
Little background, my '00 Durango Red had an issue about a month ago while driving up and around Lake Tahoe. The cluster would flash the infamous "check gauges" and the volt meter would be pegged to 18v. We would stop, shut it down and let it rest for about 5 minutes, fire it back up and every thing was peachy. Flash forward a couple of days and my wife was driving Red to work and she stopped for an energy drink on her way to work and it wouldn't start. AAA was called for a jump start and when the tech applied the jump box, Red fired right up but there was a puff of "smoke" from the alternator. He had her shut it off immediately and he checked, no more smoke from the alternator and he re-jumped it and she was able to limp it back home (5 miles or so) and I took her to work in our '01 Durango (her baby, but I'm fighting the ac and blend doors on it). Long story short I replaced the alternator with a 136 amp one from Napa. Fast forward to yesterday (Sunday)...we were at my folks house in Grass Valley and Red basically sat from late Thursday to Sunday afternoon in the heat. We left for home at about 5pm and the check gauges came back on this time showing NO VOLTAGE on the gauge. Again shut it off and upon restart it ran beautifully....approx 14 amp showing on the gauge all the way home to Reno. She drives it to work today and the check gauges pops on and the volt gauge again shows zero. I'm leaning towards a bad alternator, thankfully I got the lifetime warranty..
Question I have is, I missing something? I am going to get the multi meter out in the morning to check it and then have the alternator checked in the vehicle....any other suggestions?

ThanKS in advance

Steve

 

It does sound like a bad alternator again. I've seen two bad ones in a row from the parts stores. Pull it off and have them test it on the machine and not while in the truck (unreliable). It also wouldn't hurt to check your grounds for corrosion and think about replacing that battery.

 

Have the alternator tested. Might be a bad voltage regulator, which, unfortunately, is part of the PCM.....

 

Ack! I was afraid of that. Isn't there also a regulator built into the alternator? And if it is the pcm any suggestions on where to get a quality replacement? Is it best to send mine out for repair or is there a source to get a remanufactured one that is reliable?

Steve

 

So far as I know, I think there is a rectifier in the alternator (changes a/c to d/c) but, no voltage regulator. That's handled by the PCM. If you need another PCM, check with your local parts stores, they can generally get a reman within a day or so, and if there is a problem with it, you can walk into the store, and talk to a live human being.

 

Checking your grounds, particularly to the block may not be a bad idea either.

 

Narrowed it down a bit today. Found a loose ground on the negative battery terminal. Here's where it gets weird in my opinion. Voltage at battery 12.3 volts approx. Start the engine and it stays at 12.3 +- a few tenths of a point. Gauge shows around 10ish. Went to Aurozone and by the time I drove 3 tenths of a mile, voltage dripped ton 0 on the gauge and check gauges popped on. Shut her down, waited a bit, fired her up and it was back to the 10ish mark. Drive about a mile and boom 14 volts on the dash gauge. Went to Autozone and they tried to test the alternator, but the batter failed eventhough it shows 12.4 volts on their gauge. So back home I went. Got back left her running and was getting 13.8 volts on my multi meter at the battery. Also heard a "poofy" sound from the alternator (I know strange description but poofy is as close as I can get to describing the sound) and its a strange intermittent sound. Plan for tomorrow is take the battery back it's only 2 months old and then get alternator tested.

 

Saying it again, don't let them check alternator while in the vehicle. You'll get all kinds of answers. Last time I did that, I was told it was a bad regulator (PCM). Took off the same alternator they had just tested and brought it to them. They confirmed that it was bad on the machine.

 

Fully agree with pulling it off and testing it. Just for grins, I had the battery tested where I purchased it and it tested out fine. However, on the way to the battery shop, the check gauges was back on and reading 0 on the volt gauge. Once I got to the battery place, they tested the battery and it is almost "perfect" (his words) so went to test the charging system and when I started it, the volt gauge jumped back up to 14v and didn't drop since. Headed back home and for ****s and grins stopped at Autozone and they ran the in vehicle test on both battery and alternator and both passed. I'm currently letting it cool down so i can pull it off and have it bench tested. Told my wife it was like taking a sick kid to the pediatrician...sick as hell at home but get to the Dr office and they are fine and dandy...thought she was going to fall over laughing so hard lol. oh well the joys of 21 yr old vehicles

Steve

 

Think the alternator issue is resolved. Found the main electrical connection on the top was bad. The wire pretty much wiggled out of the fitting so it was replaced with a proper lug. I'll find out after finishing the fan resistor replacement.

Steve