Cascade Crew

fiveoformula · Posted: Sun Feb 24, 2008 8:21 pm Post subject: cooling

what is usually the problem when an electric fan wont turn on by itself?

Dewey316 · Posted: Sun Feb 24, 2008 8:27 pm Post subject:

Dual fans? There are a few things to check, there is a fan switch on the pass. side cyl head, the relay(s), and if you have dual fans, the ECU turns one on, IIRC.

--John

fiveoformula · Posted: Sun Feb 24, 2008 8:49 pm Post subject:

naw it is a single fan, so that switch on the pass. cyl. head is likely to be the culprit?

iansane · Posted: Sun Feb 24, 2008 8:51 pm Post subject:

You've checked the fan itself? Applied 12v directly to it to see it turn on?

Dewey316 · Posted: Sun Feb 24, 2008 8:52 pm Post subject:

I would guess either the switch, or the relay. The relay is easier to test, I would check the relay, then check your grounds, and if that doesn't work, then look at the temp switch.

--John

Al Hasse · Posted: Sun Feb 24, 2008 8:53 pm Post subject:

I imagine I have the same problem, except mine is shorted. The fan stays on continuous. It's a new switch too, I may have been given the wrong one. As failures go, I'd rather have it this way.

fiveoformula · Posted: Sun Feb 24, 2008 9:04 pm Post subject:

fiveoformula · Posted: Sun Feb 24, 2008 9:05 pm Post subject:

wheres the relay at?

iansane · Posted: Sun Feb 24, 2008 9:07 pm Post subject:

Look through a few of the parts catalogs that list stock switch turn on temps, I think the stock GN ones turn on lower than ours? 180 or 190 or something I can't remember.

Are you running the power for the fan through the toggle or using the toggle to flip a relay?

chevymad · Posted: Sun Feb 24, 2008 9:11 pm Post subject:

If you ground the wire going to the switch in the pass head the fan should come on. If it doesnt you need to check the relay/power supply. If it does turn on then its the switch. They come on way high, like 235. I did like Ian is saying. Went through the catalog and found one for a boat, comes on at 200 off at 190.

fiveoformula · Posted: Sun Feb 24, 2008 9:16 pm Post subject:

hey thanks for the help, im gonna try grounding it out tomarrow to see what i come up with.. as for my switch system it has no relays...

Dewey316 · Posted: Sun Feb 24, 2008 9:19 pm Post subject:

That is probably why you are burning up the switch. I put my switch on the ground side of the trigger for the relay, that way I can activate the fan manualy, or with the switch off, the system functions normaly. THe relays may be a few diffrent places, it might be on the drivers side of the firewall, up by the brake booster, it may also be near the airbox and radiator. It would depend on the car and options.

--John

Twilightoptics · Posted: Sun Feb 24, 2008 10:48 pm Post subject:

Switches need to engage the relay not the fan.

I had a single fan in my '85 Camaro and it was run by the ECM.

DBL_TKE · Posted: Sun Feb 24, 2008 11:41 pm Post subject:

Well my switch is wired strait to the battery and fan and I've yet to have a problem for over a year.