Diesel Place : Chevrolet and GMC Diesel Truck Forums - View Single Post - Reference Material: PMD
View Single Post
Old 08-02-2005, 10:15 AM   #9 (permalink)
gmctd
 
Join Date: Mar 2004
Posts: 6,945

The most common amplifier failure is caused by the increased resistance resulting from loosened driver-transistor fastener\hardware.

The epoxy potting-compound settles, reducing oem tension at the nut\screw\driver interface, electrical resistance increases, CT increases - voila !!!!

Stalling, dying - cursing - is the result.

Heat soak is the culprit.

Solution?

Remote-mounting - move 'at sucker from the engine compartment.

Period.

Temporary - sometimes permanent, depending on age and previous history - fix, is to back the driver nuts off, then re-tighten to about 5-10" - that's right, folks, INCH, repeat INCH - pounds torque.

This breaks the chromium oxides on the stainless hardware, and re-establishes the electrical continuity between the pcb and the transistor-driver case, which IS the high-current electrical path to the Fuel Solenoid.

And don't worry about the -80v spike - internal circuitry scoffs at ONLY -80v spikes.

The FSD-PMD circuitry is well-designed, no matter what the mis-informed like to complain about - it is heat-soak that does the damage.

Last edited by gmctd; 08-02-2005 at 02:25 PM.
Offline   Reply With Quote