Potential Cooling Fan Problem

[eric]

The aux. cooling fans on my 91 ZR-1 cycle ON at low speeds if the engine temperature begins to increase; however,

If I turn on the A/C compressor, the fans do not come on right away. I was under the impression that the auxilary cooling fans were supposed to come on when the A/C is turned on no matter what the engine temp.

Is this true? If so, I am wondering why mine do not come on along with the A/C compressor right away when the compressor is turned on.

Any insight is appreciated.

Thank you,
-Eric

[tomtom72]

Eric, actually I do not believe it is a straight line from the A/C compressor turns "on" and the fans ( 1 & 2 ) are turned on.

Page 6B-5 lists these inputs as having influence on fan operation:
A/C condenser pressure, coolant temp, oil temperature, vehicle speed, TPS signal, rpms, and ECM status are all listed in the FSM as having an effect on fan operation.

I know if my coolant temp is up around 220+ and I'm stopped in traffic and I turn on the A/C the secondary fan comes on to join the primary. But if I turn on the A/C at idle in open loop ( cold coolant less than 140* ) neither fan runs.

:cheers:
Tom

[GOLDCYLON]

I have to agree with Tom here. On my 91 if the AC is turned on it's not an automatic secondary fan function. It takes the other perimeters to be met as indicated above. I think the direct secondary fan rumor applies to engines that already meet the temp perimeters then it's an immediate on.