1996 Dodge Ram 1500 Van 5.2L w/automatic overdrive.
My alternator failed and I replaced it with a 110 amp alt (came with 90 amp, tried it and had following problems even with 110 amp).
- amp gauge drops drasticly under load (lights/heater) but will run ok until you put load on it or drive on road.
- Gen light stays off until load or road driven.
- Flash code check gives code 12 & 55.
- test light between neg cable and neg batt post does not come on with ign off(no short or batt drain).
- engine keeps running even though when you pull pos batt cable even gen light is on and amp gauge has dropped.
- system drains batt under these conditions.
- replaced PCM but still has same problems.
- Batt checks out OK.
- runs good until gen light comes on.

Any sugestions?
Nick Smith
Macon, Ga

 

if you have a multimeter, it would be helpful to know the voltage.

maybe the replacement alt is bad? check/clean alt/battery grounds.
check and/or replace ground pos/neg wires

 

Replaced alt with a rebuilt 90 amp alt to begin with. System put such a load on it I could see where the brushes were throwing black dust out of the alt. Took it back and upgraded to a 110 amp alt. Still have the same problem.
No 12V Batt at the scan plug so i can't use scanner.
Have noticed a extra wire spliced into wire harness at trans. running from trans. 5 or 6 wires on this plug. wire was spliced into black wire of harness. wire looked like it ran to batt at one time. However, wire was hot and not connected to batt. ?????? Why? Disconnected wire at trans harness.
Replaced PCM but replacement made no diff.
Have pulled fuses while running with charge on batt. no luck.
Checked all grounds.
Will check voltage with meter after batt charges and can crank again.

Any suggestions?

 

Fully recharge the battery first.

Rebuilt alternators, the brushes have not broken in yet. They cannot pass full current that a depleted battery will demand. They will glaze over, or pop off the commutator and get stuck in the brush holders.

Once the battery is fully recharged, tap the alternator with a hammer lightly. I bet it will start charging with 20 miles of driving.

My 89 uses fusible links. When i replaced 90 amp with 120 amp i did not charge battery first. Old fusible link Blew. It was tucked behind brake booster.

Newer vans use a maxi fuse I believe.

I once asked a reman'd alternator with 350 miles on it to recharge 3 dead batteries. It gave up after 15 seconds, and didn't start working again until I recharged all three batteries fully, and tried to make it back to the US border from mexico. 20 Miles into the trip back, it suddenly started charging again, once the brushes returned to proper contact with the commutator. Either they were stuck from overheating, or glazed from not being broken in and passing 60+ amps for those 15 seconds.

I still have the same alternator now, 8 years later, and I abuse it.

 

If it isnt a bad fuse/fusible link (would that cause intermittent low voltage?), I suspect the battery needs replacing and/or new starter/battery ground cables.

 

My van has an issue with the driver's door switch to the dome light. It isn't working, but since it started this, the battery drains. Thus, I have to figure out where and how this switch operates.

As for an altenator not working and working again, my reman unit from 2008 quit working. When I went to replace it and the belt, I had noticed the pulley was VERY stiff, thus the belt was wearing prematurely. I spun the pull the opposite direction and a chunk of something dislodged inside. From that point on, it's been working just fine.

BTW, anyone notice how these remans sound lately. There is a noticeable groaning whine that is distinguishable. AND it's not just with Dodge vans either.

Also, there should be a ground strap from the alternator to the engine block. These literally dicinergrate over time. You may just find the straps' loop under a bolt.

 

Yes, I replaced mine about a year ago on long road trip in an Advance Auto Parts lot with their higher end model they had in stock, Tough One 94604. I've noticed lately its making some slight grinding type noises, which I'm assuming is the brush contacts, fan, bearings or something. I plan to warranty it soon when I get a chance and carry a gator belt in the meanwhile since I suspect its putting undo stress on the belt drive. Unfortunately, my previous (older reman) alt was fine. I did a poor hasty diagnosis at dusk. After replacing it and still having no voltage, I discovered one of the ground cables corroded through, likely from a previously boiled over battery. Hence, my recommendations above. K.I.S.S.