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-   -   cooling fan not working - engine nor a/c (http://www.wrxtuners.com/forums/f72/cooling-fan-not-working-engine-nor-c-37257/)

fawcetteng 07-26-2013 03:59 PM

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.

history:

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.

psinuse 07-26-2013 05:09 PM

*scratches head* Now this is a question I haven't heard before...Hmmmmm...first thing have you tried resetting the ECU? second thing have you check the voltage coming from the alternator and battery?

pzr2874 07-26-2013 07:26 PM

Did you run a "grounding kit" to the same locations they are at now?

Does it still hold freon? My buddies Baja is doing ALMOST the same thing and the fans kick on right from start up (cold start up)... reason I ask

fawcetteng 07-30-2013 11:05 AM

thanks for the ideas guys- I still dont have it fixed. answers to your replies - done multiple ecu resets, tapping the brakes and what not to drain the battery. this turns off the check engine light. Battery is about 12.4 v with engine off, 13.6 ish while running, same readings with my ground lead in various places. no grounding kit installed, although i've cleaned the chassis ground bolt and the engine ground bolt and terminal on top of the manifold. the "ground" wire i added was purely to ground the fan relays manually to make them turn on, if that is what you meant.

Last night for grins I replaced the temp sensor. Now my dash gauge sits at about "normal" when the engine is cold (well, 90 texas cold), and goes off the scale at normal temp. I did a rigorous burping and all so that shouldnt be the problem. And during this time i never found my water temp above about 180 with a thermometer in the top tank. so that gets me thinking maybe my cooling fans shouldnt be coming on? Of course now i have the dash gauge problem.

Here is the funny difference - now when i turn on the a/c the drivers side fan comes on and stays on rather then switching off immediately. but the other fan never comes on.

can someone with an '04 check that both their fans do indeed come on as soon as the a/c is turned on?

my drive to work is all highway so i was confident to bring it in today, but with my fan problem and now non-working dash gauge i'm a bit hesitant to let it idle in the heat to see if the fans will switch on. they never did on the way to work.

fawcetteng 07-31-2013 01:48 PM

so I've found that both temp senders I bought in town have, for the gauge, a resistance of ~ .42 ohms at room temp. The original is around .35. This explains the gauge reading hot with the new senders.

All is back together and wired per the factory for now. will figure this out later. the one fan comes on low speed with the ac. If I pull the connector to the temp sender this same single fan comes on. I'm led to believe in both cases both fans should come on.

No CEL unless the car gets hot enough to need fans, which seems rare in my normal daily drive. The CEL is 0692, fan 1 high. i believe it is fan 1 that comes on so that doesnt make a lot of sense, except it is coming on low speed so maybe because the high speed isnt working it. If high speed is on, according to my wiriing diagram, both fans will be on high speed. there is no other way.

psinuse 07-31-2013 02:40 PM

I'm not avoiding your question, but I have been asking around to see if we can figure it out...

psinuse 08-02-2013 05:13 AM

What kind of anti-freeze are you using?

fawcetteng 08-05-2013 08:46 AM

prestone


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