heat sinks and alt repair qiuestion

[Shannen Durphey]

I found it a little funny that although GM never published any service
bulletins blaming heat for the CS alternator failures, the 96 Monte
Carlo/Lumina(W body) had a small plastic duct from the rear of the
alternator to the cowl.  After seeing that, I thought fresh intake air
to the alt. was really a "cool" idea.

Shannen

rbraun at mail.enter.net wrote:
> 
> The alt on my '91 GTA just puked, it's a CS-130 105 amp, I got it all
> apart and the way I see it the diode package grounds to the case
> through the heat sink compound.  I'm thinking the poor ground thus
> created is adding to the heat of the diode pack and helping to
> cause them to fail.   Should I leave heat sink compound off
> entirely?, or at the end where the output term connects? or add a
> ground wire?
> 
> The base of the d-pack is 3/32" thick copper plate which mounts to
> the alum case of the alt.  Would a copper to alum. mount
> transfer electric and heat better with or without the heat sink goo?
> 
> Any EE's want to give opinions?
> 
> TIA,
> Randy Braun     rbraun at enter.net
> 91  GTA
> 82 Firebird