Engine/Transmission (1998.5 - 2002) Alternator exploding???

[obert]

On the truck in sig:



Back about the first weekend of june I was sittin at a Wedy's getting the fries sorted out for my son and cooling off the cab. All ready to go, hit the clutch for reverse and suddenly it sounded like the clutch was flying appart. (Found out this was a coincedence) I shut down, re started and opened the hood (and worked the clutch, had only herd the nois from the cab at this point). Got out and was laying over hot engine getting as close to rear of engine as I could when I found out the <very loud> noise was coming from the alternator-- nearly crapped myself, it was right under my belly!



Almost sounds like an electric arc, a big one, like when the power lines along the road are hitting each other and still live, or possibly the rotor hitting the stator. And alot of ill smelling smoke from the back of the alt. I was a good drive from home and was on the way to pick my dad's camper, and needed to get back on the road. A NAPA was a few doors up the street and had a reman alt on the shelf. Drove there and swapped out alt in their lot. From incidence to fix, down only about an hour. All ok.



Fast foward to 2 days ago. We were leaving a picnic, wife wanted to go to the restroom. I went to the truck, pulled around to the restroom building to wait for wife. Then the same noise returns with the same smoke (more this time?) as before. WTF. Its been nearly 3 months but I dont drive this a whole lot- - maybe 2000 - 2500 miles on the "new" alt.



Question: Should I take the reman back? Last NAPA alt i installed it took about half a dozen to get a good one. OR is there something else under the hood (or elsewhere) that can make the alternator sound like its insides want to be on its outside.





I know its a long one, but its wierd, never herd this sound from an alternator before.

And PS: egg on my face... . 1st search here was for "alternator noise". Learned more about auto transmission TC's than I ever cared to know!:-laf

 

[fest3er]

Check the system voltage. One possibility is that the voltage regulator in the PCM has gone haywire.

Another possibility is that you have a bad connection between the alternator and the rest of the system. Or between the system and the PCM. The result could be that the PCM *thinks* voltage is low and increases the alternator's output.

You could have a battery shorting out, thus putting a large draw on the alternator. If NAPA gives you another free alternator, put it in and keep your eyes and ears tuned for electrical oddities. You might even install a digital volt meter on the dash so you can see just what the system voltage is.

You could have a bad alternator. Or three. Or you might have an electrical system problem that is frying alternators. If you're lucky, you'll find the root cause of the failure. And if you luckily detect that the replacement NAPA unit is about to fail again, go to a reputable local/regional rebuilder.

 

[obert]

I would love to have had the DVOM with me when all the comotion was going on. The volt gauge on dash didnt even flicker, light in cab didnt seem to change, but it was daytime.

So far I cant find anything out of place, but I do want to give the harness a really good check over, for fear of assult from the little 4 legged devils living in the nearby corn crib. Ran the truck for a bit yesterday, no prob. Thursday I might be able to get out after work and see if I can find a way to make prolems happen.

Hopefully this wont be one of those intermittent electrical ghosts that plagues for months.....



Oh, what is the functon of the box bolted to the back of the alternator. My service manual CD has come up MIA, not helping things any.





Thanks... .