The radiator fan in my friends 97 Cavalier is not working. The engine
light is also on, and I scanned for codes and got the P0480 code: P0480
Cooling Fan I Control Circuit Malfunction

I clear the code, and within about 10 seconds, the code comes back, fan
does not turn on.

I jumpered the relay, and the fan runs fine. I switched the relay with
the heater blower relay, and the heater fan still works, so the relay
is not to blame. I unplugged the coolant temp. switch and the engine
stalled, but the fan did not kick in. I just read on another forum that
if you unplug this, the ECM will ground out the fan as a fail safe, and
the fan should run but I don't remember this happening.

Anything else I should look for?

Thanks.

Ryan.