Please help a novice

[Walter Petermann]

> MPoore10 at aol.com wrote:
> >
> > I have been stumped by a code 53 on an '85 Corvette. The alternator is not
> > overcharging. I have swapped ecm's. The voltage at B2 is the same as system
> > voltage. I was also getting a 52 and 53. I replaced the fuel pump relay and
> > calpak. I have tried to order the factory service manual but it is
> > backordered. My Haynes manual doesn't cover this except to say it is an over-
> > voltage condition.
> >
> > I would appreciate any advice. If someone has a factory manual and a acanner I
> > would REALLY appreciate a copy of the troubleshooting procedure.
> 

Mike,
you mentioned in a previous post that you had installed a higher energy
ignition coil. Maybe it's dumping some high voltage on the + wire when it 
fires. I don't know if the ecm is sensitive enough to pick up real short 
high voltage transients. You could try supplying the coil power directly 
from the battery (through the ballast resistors if it has any), just for 
a diagnostic.

 Walter  (lots of ifs and maybes..)