In a message dated 1/21/2003 12:10:49 PM Eastern Standard Time, 
LISTSERV@GERRY.VANAGON.COM writes:

> I have an idle stabilizer that I need help in diagnosing a possible
> failed component.
> 
> The PN is 251 907 393 B
> 
> Upon opening it up, there seems to be one component on the circuit board
> that is connected to the base of the unit that looks like it is burned out.
> It is a gray resistor-looking component it looks like it says 56R 10%
> 
> Is this simply a 56-ohm resistor?
> 
       First off lets get the terminology straight.  What your dealing with 
is the Idle Stabiliser Control Unit (part behind RH tail light).  As opposed 
to the Idle Stabiliser Valve (part on top of motor).  OK, now if you go and 
check the archive over the last month or so Maybe longer we have been 
discussing the repair of this gadget so you will learn lots there.  The grey 
resistor-looking component is just that.  You can remove it and test for 56 
ohm.  I doubt it is bad.  Normally it's the power transistor that goes bad.  
Black stand up component on the right hand edge of the board when looking 
from the top and pins facing forward, fourth component down the row.  It 
should have a hole in the center and have BD 438 printed on it.  I have tried 
to replace that transistor but it did not work.  I'm not sure what the 
problem was.  The transistor the electronics store gave me as a cross 
referenced replacement was a NTE 332.  All I know the motor ran with the 
burned transistor but had idle stabilisation problems and the motor would not 
run at all after changing the transistor.  I am now using a used newer model 
of the idle stabiliser control unit part # 251 907 393D.  Idle is still 
erratic at cold start up but fine after temp needle starts to move.  I've 
been busy in the shop with paying jobs and it's been far too cold to fool 
around with this so I have not done any further investigations on this 
matter.  I do plan to though soon as I get some free time.  I would 
appreciate any feed back you can add to this investigation from your end.  
There are others on the List working on solving this problem and I'm sure 
you'll hear from them also.  Hopefully someday we will get to understand and 
be able to repair this expensive item.  Good luck.
       
Cheers��

Frank Condelli
Almonte, Ontario, Canada
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