[V8] early alternator diagnosis

dsaad at icehouse.net dsaad at icehouse.net
Thu Apr 29 17:26:53 EDT 2004

It is a straight forward job -
take it off
fix it
put it back on

You probably oughta do the usual double check of fuses, cable connections, etc 
but R&R of the alt is basically:

- remove batt ground cable
- Remove belly pan
- I remove the accessory belt shock damper outer bolt (to free up one end) 
because it is easy and it makes the rest of the dealings with belt much easier.
- Using a 13mm socket or wrench, de-tension the belt and lock in place with a 
pin such as a 9/32 drill shank. The location of the locking hole is hard to 
describe but while holding the tensioner compressed, you can slide the drill 
shank along the side of the tensioner bracket and it will fall into the hole.
Take a good look at the belt routing - it is wierd.
- remove the remaining wires and bolts from the alternator and you are done.

If you are going to DIY the alt repair:
The brushes are not easily replaceable. You can do it if you find the right 
size and can cut the old ones out and solder in the new. Otherwise just replace 
the voltage regulator. You can file down an over sized brush very easily. This 
is way cheap (like $0.50 for both brushes) but takes time.
Finding the exact brush will be near impossible.
Get good quality bearings designed for this purpose. They are usually specified 
as electric motor grade. These usually have more balls, better seals and grease.
Clean up the slip rings with a little steel wool and that is it. If you do not 
have any winding shorts or diode problems then you are good as new. I would 
bring it to a shop with a good tester to make sure it is working OK befor  I 
put it back in.
If you do have diode problems, they are replaceable. If you have winding 
problems, you probably just want to buy a remanufactured unit. Neither of these 
is a common problem.


Quoting "Coleman, David" <David.Coleman at blackrock.com>:

> Driving along last night (on the way to the hospital of all places) when
> the battery light comes on in the early warning display.  Few miles
> later the anti-lock light comes on.  Lights start getting dim, power
> steering gets heavy.  Lady with a baby in the right seat, so I just
> pushed on.  As expected, it wouldn't start after shutting it off.
> Two hours later, it started back up, but still with barely any voltage
> (30-second windows, e.g.).  Made it the five miles back home thankfully.
> Gotta figure the alt stopped charging.  I just moved a couple weeks ago,
> and my manual (and computer) are still packed away, so I'm going in
> blind.  Does anyone have any must-know BTDTs on the alternator R&R?
> Thanks,
> DaveC.
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