That's exactly what I thought, amazing.
Harry Watkins
Newton, MS
86 SDL Silver
85 300D Euro
86 SDL Gold
81 240D manual trans
- Original Message -
From: Jim Cathey [EMAIL PROTECTED]
To: Mercedes Discussion List [EMAIL PROTECTED]
Sent: Friday, March 24, 2006 10:52 PM
Subject: [MBZ] Vacuum cruise controls
I have learned that the set speed, held as charge on the FET's input
capacitor, is stored as a Idelta/I from approximately 60 MPH.
That is, Vcc/2 is the initial output voltage of the error amplifier,
and this is approximately the voltage out of the tachometer circuit at
60. So if you have a cruise control that always seeks out about 60
MPH when set it may be that the FET (a BSV81) is shorted, or that the
K2 relay (responsible for setting the speed) is stuck on.
I think somebody complained about this in their SL, and resoldering
had never fixed his problem.
-- Jim
