A/C Only blows cold when radiator fan comes on?? plz help

[CTScott]

Originally Posted by metalshark

The ECU cannot directly turn on the fan. A relay must be used to source that much current. It is unlikely that the relay has an auxiliary set of contacts to notify the ECU when it has failed. On my Yaris the fan comes on every time I turn on the AC.

The ECM controls the cooling fan via a relay (I did not say that it does not have a relay, just that the ECM has complete control over this process). Normally this does happen when the AC is turned on. The AC tells the ECM via CAN bus message that the AC compressor is running (the AC ECU fires the compressor directly, without a relay) and the ECM turns on the fan via the fan relay.

Since the OP's fan and compressor both turn off, my suspicion is that the AC ECU is logging a DTC and shutting down the AC.