Questions and Answers
Accord Cooling Fans
Q. Dear Vincent, I'm a backyard mechanic and here is the problem that is stumping me. Recently the condenser fan and radiator fan are always running on our 1991 Honda Civic DX sedan. Normally this should only be the case when the A/C is on. This is a new problem so no one wired it this way.
I have spent a whole day troubleshooting and still no answer/solution. I've checked both relays by swapping them with a known good one, I've pulled the A/C diode and only the condenser fan shuts off, I've checked with an ohmmeter for wires shorted to ground, I even popped off the lid on the ECU to see if any components were fried that are inline with the fan relay output signal and the A/C on input signal.
Can you help. I have a complete wiring diagram and multimeter. If it helps and you are willing I could scan the schematic and send it as a PDF to you.
1991 Honda Civic DX
1.5 liter
Automatic transmission
114,000
P/S, A/C, no cruise controlBest regards,
ElliotA. From what I see on the diagram, I would suspect a bad A/C diode pack. It's located under the dash on the right side. You can test the diodes with an ohmmeter and make sure they are good.
Now in this system, there is always power in the circuit. The various switches provide the ground to complete the circuit. Since both fans come on, I would start looking for a short on the A/C side. That would include the A/C Thermo Switch, Fan Speed Control Switch or the wiring from the condenser motor (blue/red wire).
Additional Information provided courtesy of ALLDATA
