AC question 5KCSTQ

[Ti Kan]

John Sherrow writes:
> Well it's getting warm and of course the AC isn't working.
> Relay 11 is not switching voltage to the compressor.
> 
> 12 volts is on one side of the Relay 11 coil. The 12 volts is  is routed =
> thru the AC low pressure switch. The other side of the coil is high =
> impedance. Is this a switched ground? If so what switches it?
> 
> My Haynes manual shows the low pressure switch running right to the =
> compressor with no mention of relay 11.=20

The Bentley wiring diagram shows that both connections of the Relay 11
coil going to the AC programmer.  In other words, the AC programmer
controls the relay activation.  One of the relay "switch" contacts goes
to the fuse/relay panel's internal "X-contact" line (which has 12V when
the ignition switch is on but not in the "crank start" position).
The other switch contact goes to the AC low pressure switch then
to the compressor clutch.  The compressor clutch is grounded to the
engine block.  It is switched 12V, not switched ground.

If you're getting 12V at one pin of the low pressure switch, then
the relay is working fine.  If there is no 12V on the other pin
of the low pressure switch, then your AC probably needs charging.
Otherwise, there may be a wiring or connection break to the compressor
clutch.

-Ti
-- 
Ti Kan
http://www.amb.org/ti
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