My radiator fan does not cycle on with the compressor. The result - if the car is standing still, the compressor will run until the high pressure switch trips. The condensor simply can't cool the r-134a fast enough.

I have done troubleshooting on the fan ... the fan DOES work, both speeds. I have tested the fan relay, and both the high and low speed 'ground inputs' will turn on the fan. Also, the fan will kick on when the radiator temp increases (I disconnected the low speed input so the temp would rise enough at idle to kick in the high speed fan).

Possible solution - I think that the contol unit that trips the fan's inputs is either not recieving the signal from the A/C compressor circuit, or it is not correctly closing the fan circuit when the compressor kicks in.

Where can I find this control unit (My haynes Manual calls it .. um, the ezk (di) efi control ... or some such)?

Any other ideas on what is keeping my fan off?

Thanks!