my altenator is ok... damn.

[blathan]

ok so i jumped the gun today. lately my charge guage was hovering around 19 volts. today going down the highway, it went to the other end of the guage, the tach and the speedometer cut out, then engine. fun times. took the altenator off and took it to autozone which tested it and said it was fine. what can cause it to over charge like that and then cut out like that. I can't start it now, I had to replace the starter about 15k miles ago. what should i look at next? wires? fuses all looked good. no break in the fusable link with a volt tester.

 

[Lodi Jim]

Alternator sounds as if it is losing it's diodes(regulation part),it will be intermittent until it goes south. Change the alternator.

 

[blathan]

Alternator sounds as if it is losing it's diodes(regulation part),it will be intermittent until it goes south. Change the alternator.

is there a way to test the diodes?

 

[JJacobs]

The tester checks 'em, back to the whole 'intermittent' thing. I've had that happen a couple times, change out the alternator and you'll be back in business.

 

[Matthew Currie]

You don't mention the year. If it's a pre-91, it has its own voltage regulator, but if it's a 91-up voltage regulation is by the PCU (engine computer). I would check all the wiring to the alternator very carefully for shorts and opens before condemning the alternator, especially on a later one. You should also do a thorough check of the battery connections, grounds, etc. Don't forget to check the braided line from the rear of the engine to the firewall, which often corrodes. The battery is a necessary part of the whole voltage regulation business, and filters the output of the alternator. If the battery loses connection while running, or if it's really bad, you can get an overcharge condition, and Chrysler injection systems just hate the choppy high voltage you get from an unbuffered alternator output.

 

[Brian Carpenter]

Any clue what ccaused the demise?
I just lost another one due to MUD killing the bearings.

Has anybody figured out a fix for this?

 

[RedHeep]

Any clue what ccaused the demise?
I just lost another one due to MUD killing the bearings.

Has anybody figured out a fix for this?

Don't drive in mud?

 

[87manche]

Don't drive in mud?

x2
or relocate it to where your AC compressor is.