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obd2-obd1 ac trbls

Posted: Sun Aug 18, 2002 4:21 pm
by ronin
i have a trbl where when i use my hondata obd1 ecu with harness, the ac is not seeing the signal to kick the compressor on. when i use my obd2 stock ecu it runs. i got so frustrated i pulled the condensor, compressor, and so on. i want to use my ac again, and was wondering if anyone else ran into a similar problem. this started about 18 months ago, and doug i discussed it with doug at the time.

any ideas? i only have 2 wires running to my compressor.

A/C control

Posted: Sun Aug 18, 2002 9:52 pm
by Hondata
The ECU gets the A/C signal from the A/C switch / thermostat, and outputs a signal to the A/C clutch. Check the wiring on the adapter harness by looking at the OBDI and OBDII wiring diagrams, then checking that the right pins are connected together. You should then also check the signals are getting to the ECU with a multimeter (cation: some signals are grounded when active, 12V on the ACC wire does not mean the A/C clutch is on). If that all looks good then it could be the ECU itself - something nasty might have happened to the output transistor for the ACC.

Posted: Sun Aug 18, 2002 11:28 pm
by ronin
yes, i checked and rechecked the harness, kenji even told me which pins to check, i found one of the wires had a loose conection to the pin, re-jumped it and nothing. in the end it may have been an ecu trbl, i never ran it until after it was chipped. was just wondering if anyone else ran into something similar.