Huntsville 3500

Howdy all,

2003 3500 TCD, 126K, Auto, Started the truck today & within 5 minutes of running the check gauges light came on. Looked & found the alternator gauge pegged to the left. Continued my trip, was only going another few miles. Looked under the hood, belt was there, all connections are tight. Started it up and it went back to 14+ on the gauge. Got back to the office and started it a few times and noticed it went to 14 but took it's time getting there. I won't swear to it but in the past I think it went to 14+ almost instantly.

I thinking my alternator is dying. Is there anything else to check before I buy & replace the Alt? I was going to let AutoZone put it on the meter but I think that since it is working again, they won't show any problems....


All comments welcome!

Thanks

Vic

Lost Lake

Sounds like the regulator is going.

tesla440

The only things to check on the alternators these days is the voltage to the alternator. There should be a two wire connection (black & red). You'll need to make sure that you have the correct voltage going to it. I believe it's 12v. But check the manual. I'm going to guess though it's the alternator.

justin allan

mine did the same thing and I just replaced it and it is working like it should. I had 204k on it when this was happening so i figured it was time. I drive alot of miles in one day and did not want to be stranded anywere.

Huntsville 3500

Is the regulator internal to the altenator?

Lost Lake

I don't know. In this throw away world probably. In the day we would swap out regulators and rebuild starter solenoids.

But it sounds like the regulator. I'd get it replaced before it fries your batteries.

Huntsville 3500

I hear ya... when I was a kid, I would have tore it down & replaced the brushes. I replaced the alt last night. $140 from auto zone.. The new one was stamped "external regualtor" AZ didn't list a regulator for the truck. I'm thinkin the black plastic box on the backside of the alt was the regulator. It actually started workin again but I took it as a sign it was dying slowly. Better to replace it now than risk killin two expensive batteries & getting stuck somewhere cause you know it will happen on a rainy Sun nigt!

.boB

I could be wrong, but I think the regulater is inside the main ECU.

Huntsville 3500

I considered that possibility...Already replaced the altenator, cross my fingers that was it. Showing a rock steady 14 plus on the gauge. Mulitmeter reads 14.36 at both batteries. Should be good to go...

thanks for all the input