Join Now
International Automotive Technicians Network
Catastrophic Alternator Failure
Posted to Technical Discussion Forum on 5/13/2017 36 Replies

Hello, this is strange, and dangerous, to say the least. An IATN member contacted me about a 2014 Grand Caravan, with only 54,000 miles, that wasn't charging at all, and no MIL, no charging codes. OK, to begin, there is a recall on Chrysler products with the 160 amp alternator, that have sudden, and dangerous alternator failure, that sometimes catch on fire, and can burn the vehicle to the ground, and can be dangerous to drive when this failure occurs, and frequently no MIL, and no battery failure light. This vehicle is not on the list.

So now the question is how to quickly determine if the alternator is bad. How to know for sure without messing around. This is the new "B" Chrysler charging system. On the alternator there are two small pins. One should measure 2.4 K ohms to the output post, and the other about 3 ohms to rear alternator case. One pin measured 2.4 K ohms to output post, but the other measured 1,400 ohms to rear case. I was going to suggest a full field test, but no, the field circuit is blown, so no reason to do this.

My friend removed the assembly. The brush unit and terminal assembly are held into the rear case by four screws. Initially the brush/terminal assembly would not lift out. Why? There can be only one reason. Extreme groves in the slip rings, that why. Finally my friend extracted the brush unit. I never ever, in fifty five years of fixing alternators, saw slip rings this badly gouged out. They were completely destroyed, and at only 54,000 miles.

So why no MIL, no battery light, and no warning? I have no idea. Why this extreme failure at this low mileage, no less on a Denso? Denso alternators are known to be extremely good.

I can't post the pictures of the extreme slip ring damage because I don't know how to do this. But my test, to measure field continuity, and integrity of the sense line, takes almost no time at all. If it fails this test then you don't even have to think about a full field test. This is a 100% test. If it fails you can be 100% sure the alternator is bad. Louie

Louis Bernstein
Owner/Technician (Retired)
Louie's Service
LeRoy, New York, USA

36 Replies Received (View Replies)


car Vehicle Data

2014 Dodge Grand Caravan SE Plus 3.6L

Engine3.6 L
Trans6-speed Automatic (Electronic)