In a message dated 07/01/2007 7:05:03 P.M. Eastern Standard Time,
LISTSERV@GERRY.VANAGON.COM writes:

My other  bet is that if an IS valve shorts, it will blow the transistor.

How  many folks out there have a *bad* IS control unit? I'd love one to
verify  if it's the transistor that went south.

Your "guess" is correct.  I have four  dead ones on the shelf in front of me.
 There were six here but I sent two  of them to another "researchist".  All
of them have that transistor burnt  out in them.  And it sure seems as if the
Idle Control Valve sticking  overloaded the circuit and caused the transistor
to burn.  In the newer  version of the Idle Control Unit, with "D" designation,
we see there  are two transistors on a big heat sink, wonder why ?  I've
never seen a  burnt out newer ICU.  Now, I've tried replacing that BD438
transistor and  have had no luck.  Maybe there are other components on the board burned
out  on the ones I tried, don't know, so I gave up experimenting.  Looks like
 the ball is in your court.

Cheers,

Frank  Condelli
Almonte, Ontario, Canada
'87 Westy, '90 Carat, '87 Wolfsburg  (Forsale) & Lionel Trains (_Collection
for  sale_ (http://members.aol.com/Fkc43/trainsal.htm) )
Vanagon/Vanagon Westfalia Service in the Ottawa Valley
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