heat sinks and alt repair question

[Terry_Sare at dell.com]

You will fry the diodes if you do NOT use heat sink compound, period. The HS
grease lowers the thermal resistance of the metal to metal contact. There is
plenty of metal to metal to conduct the current. If you think there is a
contact problem, measure it with a good DVM between the diode and the case.
Should be almost 0.

Again -- do not skip the heat sink compound.

ts
> -----Original Message-----
> From:	JRECPA at aol.com [SMTP:JRECPA at aol.com]
> Sent:	Monday, September 21, 1998 11:28 AM
> To:	diy_efi at efi332.eng.ohio-state.edu
> Subject:	Re: heat sinks and alt repair qiuestion
> 
> In a message dated 9/21/98 9:12:19 AM US Mountain Standard Time,
> rbraun at mail.enter.net writes:
> 
> << 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
>   >>
> Be sure to put plenty of heat sink compound back on the diode pack.
> 
> I'll bet that your alternator's back is blocked buy engine components
> that is why the diode pack is overheating, no air flow!
> 
> James