cooling fan not working - engine nor a/c
'04 WRX 2.0 manual
i've searched the threads on this but cant find a solution to my problem. When I turn on a/c, the drivers side (left) cooling fan comes on for a split second then stops, despite the a/c staying on. Sometimes, but not always, when the engine gets hot the fans wont come on. and by hot i mean the needle past the 2/3rds mark and still climbing. any ideas? here is what I have done and some history.
CEL 0691 is on, but see below for when this happened.
both fans will work appropriately if i ground any of the four relays. this means the relays have power and are working, and the fan power circuit is good, all of which i checked anyways. In fact to get around this issue in the meantime I've run a ground wire into the cabin with a switch to turn them on when needed.
My first thought has been that there is a break or bad connection for the ground wires that go to the computer to switch on the relays, although I thought it must be intermittent as sometimes the fan will come on to cool the motor. so I ran secondary set of wires to the computer to test this. did not help. also, the factory wires tested good.
the car is new to me, my first summer. in the spring we took it to Big Bend in south texas and there i had overheating issues. first time was when it was sitting still for 10 minutes with the a/c on, 100 ambient temperature. I thought maybe the cooling system just cant handle that, I didnt notice if the fans were on or not then (wasnt familiar with the car). I was disappointed that this was happening, but being use to old british cars i just turned off the a/c, on with the heat and got her moving. it cooled down slowly. then i tried the a/c but it wasnt really cool. later the same day the a/c was fine and the engine stayed cool. this repeated then next day, but without the sitting still at the beginning.
fast forward to summer and the first time i really need a/c and i found it to be in bad shape- luke warm air. still wasnt paying attention to the fans. so, being 9 years old i just thought it needed a recharge. i took it to the shop who said it was low. they said they didnt find any leaks but that the right fan wasnt working and maybe it was over pressurizing and over time vented the freon. they also said one relay was broken, but i think they fat fingered it and broke it themselves. its hard to get those relays out. i think they were wrong on the fan also as they both do work, and the relay they broke was for the high speed of fan 2, which on my car you need relay 1 on before there is power at 2. THIS IS WHEN THE CEL CAME ON, which they explained as because the relay wasnt there. relay is replaced now but cel continues.
with both fans on with my extra ground the newly charged a/c is barely adequate, not really cold till the sun goes down. maybe normal for 100+ weather? also, when the a/c compressor cycles on you can feel it, car almost feels like it sneezes. before the big bend trip i replaced the belt and had to tighten it more then i liked to keep if from slipping at this compressor startup phase. it seems like the compressor takes a lot of power to get it started.