Where can I possibly find an auto-electric technician in the Dumaguete area that is capable of reading a wiring diagram? I have an A/C problem with my car (condensor fan stays on and kills the battery - intermittent) that nobody seems to be able to diagnose. I would like to try arbitrary parts replacement, but I need to know where to start. There are thermistors, pressure switches, resistors, relays, etc in the system but I can't figure out the routing. I would like to replace the most probable (and cheapest) parts, first or ideally, find somebody that can actually troubleshoot with a multimeter. The techs that I have met tend to add another wire to the ignition circuit and bypass anything complicated, thus compounding the problems.
Hi Steve, I use to own an auto elec shop / air con specialists, but I am not a sparky, there are many causes for your problem, sometimes the ECU is in a limp home mode, depending of the breed of vehicle and its age, try disconnecting the battery for about 60 minutes, it won’t be your high low pressure switches as they will shut down the A/C if they fail or the gas is low or high. Does the cond fan run all the time when the engine is running without the A/C on? There are on a lot of cars that have separate ECU / computer that controls the A/C, this could have failed? I have in the past had to bye pass such controls due to the customers financial status, a lot have this on the main ECU, in that case if this circuit has failed then the main ECU needs replacing, then you need a tech that has the gear to tap into your ECU and read the fault codes, again depending on the breed and age of your car. A relay can be at fault sometimes a gentle tap after the ignition is off may stop the cond fan from running, if so you have found the culprit. Be careful probing around with test lights or analogue multimeters as they have been blamed for setting off air bags.
Thank you, Shultz, for the great info. My car is a '97 Suzuki Esteem. It is not a Japanese conversion and that model was not originally sold in the Philippines. It does not have air bags nor ABS and the ignition system difers from the Canadian / American version of the same car (mine has the old distributor with rotor). The condensor fan is wired through a 30 amp relay that is labeled ABS on the cover of the fuse / relay box. My owner's manual says the motor requires a 50 amp relay (none available here that would fit that particular plug) so maybe I should start by providing a relay circuit with the proper amperage? Update: While writing this reply, I went out to verify if the condensor fan was on when ignition is on. The answer is no; it is wired to the blower motor switch. However, the radiator fan is wired to the ignition. Now, it gets interesting! By accident, I hit the power window button after the key was turned off and the condensor fan was stopped. When I hit the passenger window "down" switch, I heard a "click" and the condensor fan started and remained on! Following your advice, I tapped on the fuse box and the fan stopped. I can repeat this operation at will. I replaced the relay and I can still turn on the condensor fan with the light switch but the fan goes off when I release the switch. I have a sticky window switch that sometimes sticks in the "up" position. I am guessing that this switch, while stuck "up", activated the fan and subsequently burned / weakened the relay. So, I guess that if I: replace the relay again, lubricate the window switch, and find how power from the window switch (with key "off") is actuating the fan, the problem will be solved. Thanks for your advice, Shultz.
Thanks anyway, but the diagrams I have may not be complete. They came from a Russian website and my car may not have the same installation. I am pretty sure now that something is mis-wired in the electric window motor switch that sends power back to the condensor relay, even whenn the key is off.
You are welcome. Not only think about the positive lead circuit that powers the fan(s), but also the negative lead, unless it has a simple chassis ground. An erratic ground, or negative circuit can cause all kinds of goofy problems that don't seem logical.
