Engine fans won't come on, charging system repaired.

Mephis · #1 07-30-2009, 11:58 AM

Yep, well you know how my engine fans wouldn't come on and how it would overheat since my charging system wouldn't work in the last thread?

Well, I have a new alternator in, charging between 13-14 volts as it should be, but now the car's engine fans still refuse to come on.

Getting tired of this... Anyone have any advice? I checked all the engine compartment fuses and they're fine. I have no way to know if the relays are good. There's no check engine light.

It gets to operating temp, the gauge stops going up, even though the car overheats and the fans won't kick on.

BoxerFanatic · #2 07-30-2009, 12:03 PM

Could be fan relay...

but if the gauge doesn't show an over-heat, maybe the temperature sensor never trips the fans to come on, and doesn't tell the gauge to rise ...

SoCal LS-L · #3 07-30-2009, 12:03 PM

Quote:

Originally Posted by Mephis

Yep, well you know how my engine fans wouldn't come on and how it would overheat since my charging system wouldn't work in the last thread?

Well, I have a new alternator in, charging between 13-14 volts as it should be, but now the car's engine fans still refuse to come on.

Getting tired of this... Anyone have any advice? I checked all the engine compartment fuses and they're fine. I have no way to know if the relays are good. There's no check engine light.

It gets to operating temp, the gauge stops going up, even though the car overheats and the fans won't kick on.

Theres a coolant temperature sensor just below the intake manifold on the drivers side, at the rear. Resistance test this when the car is fully hot and compare the reading with whats in the service manual.

I think the fans are actually supposed to come on automatically if the sensor is disconnected, so you might unplug it while its running and see if that kicks them on. If so, then the sensor is a likely problem.

Also the temp gauge is controlled by the temperature sender, which is seperate from the sensor. The gauge not registering an overheating condition is a common problem with resistance field gauges, they develop a magnetic "memory" of the spot they sit at most (normal operating temp), and will stay there even with a lower resistance signal. Thats why a lot of new cars peg their gauges to the max and back down when first started, to keep the resistance arc functioning properly.

Mephis · #4 07-30-2009, 12:07 PM

Unplugged the temp sensor at the back on the driver's side. Fans kicked on.

I guess that means I'm ordering a temp sensor, right?

SoCal LS-L · #5 07-30-2009, 12:09 PM

Quote:

Originally Posted by Mephis

Unplugged the temp sensor at the back on the driver's side. Fans kicked on.

I guess that means I'm ordering a temp sensor, right?

Correct, mine was like $26 from Autozone, but you might want to try a few different sources. A lot of people suggest OEM, but my $26 sensor functions just fine, I think its Beck & Arley or something.

Mephis · #6 07-30-2009, 12:10 PM

Thanks for all the help. I'm calling around to try and get one today but yea autozone has that one for that price if all else fails, have to order it though. Going to check with a subaru dealership and see if I can't get anything today.

*edit*
Found it for $23 and they're going to be able to get it in today.

Manarius · #7 07-30-2009, 12:11 PM

Quote:

Originally Posted by SoCal LS-L

Correct, mine was like $26 from Autozone, but you might want to try a few different sources. A lot of people suggest OEM, but my $26 sensor functions just fine, I think its Beck & Arley or something.

subarugenuineparts.com has them for like $20 something dollars. However, the Autozone one will work if you desire instant gratification.

SoCal LS-L · #8 07-30-2009, 01:28 PM

Quote:

Originally Posted by Manarius

subarugenuineparts.com has them for like $20 something dollars. However, the Autozone one will work if you desire instant gratification.

Mmmmmmmmmm, instant gratification

Mephis · #9 07-30-2009, 04:23 PM

Welp, replaced the part, no change. I said many colorful words and gave the garage some character, then limped the car to a subaru dealership. No more goose chases.

SoCal LS-L · #10 07-30-2009, 04:39 PM

Quote:

Originally Posted by Mephis

Welp, replaced the part, no change. I said many colorful words and gave the garage some character, then limped the car to a subaru dealership. No more goose chases.

Thats quite odd, you confirmed the fans came on with it disconnected, so there was no power issue, just a signalling issue. Did you by chance resistance check either sensor? There have been known cases of bad "new" coolant temp sensors.... Oh well, let us know what the dealership says....

Mephis · #11 07-30-2009, 06:02 PM

They refused to refund the sensor anyway.

Doesn't matter if it's good or bad, I'm still ****ting money away chasing down problems I have no way of making sure of. Dealership is probably going to have me eating ramen for a few months but what has to be done has to be done. I would sooner assure the car is in good health than I am lol. It will probably outlive me.

SoCal LS-L · #12 07-30-2009, 08:09 PM

Quote:

Originally Posted by Mephis

They refused to refund the sensor anyway.

Doesn't matter if it's good or bad, I'm still ****ting money away chasing down problems I have no way of making sure of. Dealership is probably going to have me eating ramen for a few months but what has to be done has to be done. I would sooner assure the car is in good health than I am lol. It will probably outlive me.

Well thats why I suggested testing it before replacement. A good multimeter will go a lonnnnnng ways in helping finding sensor and general electrical faults. I also hate throwing money away replacing parts trying to chase down a problem, so I usually test until my fingers bleed to confirm a part is bad. Hopefully the dealership is respectable.

kwren · #13 07-31-2009, 12:24 AM

Quote:

Originally Posted by SoCal LS-L

Well thats why I suggested testing it before replacement. A good multimeter will go a lonnnnnng ways in helping finding sensor and general electrical faults. I also hate throwing money away replacing parts trying to chase down a problem, so I usually test until my fingers bleed to confirm a part is bad. Hopefully the dealership is respectable.

Unfortunately, respectable doesn't mean that the "mechanics" have a clue

Keith

Mephis · #14 07-31-2009, 12:28 AM

I put a multi meter on it and couldn't find a setting to get any sort of reading.

Because of exactly what you said, my car is at the dealership now. I can't afford to keep wasting money even if it costs a little more.

Plus the way the car was hesitating when accelerating driving over there has me extremely concerned. I can tell all the power is there but something is trying to limit it. I guess that's limp mode since I had the temp sensor unplugged?

Mephis · #15 07-31-2009, 12:31 AM

Quote:

Originally Posted by kwren

Unfortunately, respectable doesn't mean that the "mechanics" have a clue

Keith

I'm willing to bet they have more of a clue than I do.

It's got more miles on a trailer this week than on the road, so apparently I can't get it fixed. Fix one thing, something else goes to hell, etcetc.

On the plus side the new alternator pulley is chromed and matches my aluminum crank shaft pully...