Don wrote:
Marshall,
What controls the cycling on/off on a W123? Is it a pressure switch or
a temp switch? My electric fan is "good" (I can jump the relay and
make it run) but it doesn't come on when the ac is operating. I don't
think it is a relay problem after doing some troubleshooting.
The 123 aux fan is controlled by a temp switch - when temp exceeds 50-60
deg C (don't recall precisely, but it's a temp that corresponds to ~ 280
psi). When the fan comes on the temp drops, the fan goes off until the
temp goes up to the trigger point again. On a very warm, humid day the
fan may be on MOST or even all of the time, on a cool day it may seldom
if ever come on. On a 123 the switch can be changed without draining the
system (with 124/201s the system must be emptied to change the pressure
switch that's used).
Marshall
--
Marshall Booth Ph.D.
Ass't Prof. (ret.)
Univ of Pittsburgh School of Medicine
Department of Pharmacology 1300 BST
Pittsburgh PA 15261 USA
[EMAIL PROTECTED]
