Heat sink compound

Randy rbraun at enter.net
Mon Jan 11 15:50:06 GMT 1999


The positive diode pack is stacked on top of the negative diode 
pack and the whole thing is screwed down to the case with three 
screws, all of which have plastic insulators on them, obviously 
needed since the screws pass through both diode sets.  The neg 
side is to conduct to the case just by clamping pressure to the 
case but this is through a layer of HSC.   Maybe Delco used a 
conductive HSC, but the factory stuff is the same white looking 
stuff I've always seen.

Negative diode failures are the most common cause of death for 
these alt's.  There is a new aftermarket design out, summit sells it, 
called the "iceberg"  It has fins on the rear case where the diodes 
mount.  I think my extra screw or conductive HSC , if I could find 
that, is the way to go.   105A is a lot of current to push through a 
resistive connection.


> 
>   Also , how is the negative diode in your alternator connected to ground? I
> understand that you have no screws to ground it , except the 8-32 that you
> have added. I am certain that Delco intended to provide a GOOD connection
> between the negative diodes and ground --- in a negative ground alternator.
> 
>   Or -- Have I misunderstood something here??
> 
>        Jerry
> 


Randy Braun     rbraun at enter.net
30th Ann. T/A coming soon....
91  GTA   for sale
82 Firebird



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