Diode ID

[Ludis Langens]

Matt S Bower wrote:
> 
> Need help here.  I have a 6870 with a blown diode.  If any of you guys
> can help me I would be greatful.  It's labeled CR1 on the board and it's
> a small glass diode.

CR1 is part of a circuit that clips negative voltage spikes on the ECM
power input.  Check this schematic page (the 6870 and 7170 use the same PCB):

  http://www.cruzers.com/~ludis/1227170sheet7.gif

You probably need something that can conduct the current of a rectifier
and switch at the speed of a signal diode.  If you want to use a genuine
GM diode, most (all?) C3 generation ECMs have this same circuit.  You
could pull a replacement from something other than a 6870.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/