Electric fan questions!

[natas13]

So I'm going to get an electric fan setup in my c10 and was wondering why everyone runs them on a thermostat and such instead of just hot wiring it to a switch in the truck so you can just turn it on when you need to?

[Lee H]

I run mine on a thermostat so they go on and off as required automatically, I don't want to be watching the a gauge that may or may not be accurate. I know a few guys that have forgotten and turned them on when they smelled antifreeze. One guy only lost a hose and some antifreeze but was stuck on the side of the road, the other lost a head gasket for sure, maybe a head, he has not taken it apart yet.

For what it's worth, I've run my dual electric fans for 2-3 years now. I've had two relay failures and one fan motor failure in the last year. I'm likely going back to the stock clutch fan set up.

[natas13]

I've done just a switch with other cars as well just curious. How did you run your thermostat? I'm going to get rid of my clutch fan and just run electric and I saw the jeep grand Cherokee fan setup I might just run that in my shroud alone. Is this good or bad idea?

[Norcal72]

Use a thermostat switch. If will allow fast warmups. Or wire always on with ignition. I wouldn't use a simple on/off switch, like mentioned you'll forget one day and it can get ugly quick.

[Lee H]

I'm using a Derale controller part number 16789 right now.

[LSUMurse]

I am WWWAAAAYYYYY too dumb and forgetful for that. That is a sure fire way to have me calling AAA for a tow.

[joey8383]

http://www.summitracing.com/parts/sum-890015
Here's one from Summit. Might be able to shop around and find just the thermostat switch cheap and supply your own relay and wiring if you needed to.

[RManson]

Another vote for a thermostat switch. The fans on my supercharged LS rarely if ever run over speeds of 30-40 mph as the air flow through the radiator is sufficient enough to cool.

Fans, batteries and alternators are expensive, why further tax them by running the fan full time?

[MARKDTN]

Originally Posted by RManson

Another vote for a thermostat switch. The fans on my supercharged LS rarely if ever run over speeds of 30-40 mph as the air flow through the radiator is sufficient enough to cool.

Fans, batteries and alternators are expensive, why further tax them by running the fan full time?

Are you running it through the PCM and letting it control fans or a separate controller?

[RManson]

Nope. I can but chose not to for simplicity sake. I installed a thermostatic switch in the bottom of the radiator (near the outlet) and wired it directly to the fan relays.

Originally I was going to wire them to the Holley Dominator ECU and let that control them but after speaking to Jeff at Painless, he recommended this as it's incredibly simple and consistent.

[jeh]

I wired mine with a thermostat and also tied it in to my A/C switch so when the A/C turns on the fans turn on also.

[nightmare]

Originally Posted by jeh

I wired mine with a thermostat and also tied it in to my A/C switch so when the A/C turns on the fans turn on also.

How did you tie it into the A/C? Do you have a wiring diagram, or maybe some pics?

[jeh]

Originally Posted by nightmare

How did you tie it into the A/C? Do you have a wiring diagram, or maybe some pics?

I have Old Air Products A/C complete system installed on my truck instead of "factory" air. There is a wire that runs to the compressor that turns it on when the a/c is turned on, I just tied in to it. In your case you need to find the hot wire that runs to your a/c compressor and then you tie in your fans. I also forgot to say that I do have a fan control mounted beside the radiator. Hope this helps..

[nightmare]

Originally Posted by jeh

I have Old Air Products A/C complete system installed on my truck instead of "factory" air. There is a wire that runs to the compressor that turns it on when the a/c is turned on, I just tied in to it. In your case you need to find the hot wire that runs to your a/c compressor and then you tie in your fans. I also forgot to say that I do have a fan control mounted beside the radiator. Hope this helps..

Did you run it off a relay?

[jeh]

Originally Posted by nightmare

Did you run it off a relay?

Yes, I bought a electric fan relay kit for my fans.

[RManson]

Use a trinary switch...