Electric fan over ride

[RLAM]

My 6.5 application is a 97 Trek motor home and it has a single blade electric fan in front of the radiator. It is thermostaticly controled. I do not know at what temp it comes on (not paying enough attention) and my thought is to install a manual over ride so that I can turn the fan on before engine temp starts to go up. If you know you are going to make a hard pull, you flip the fan on.I am not an electrition and am looking for some help with the instalation(boy, I wish this thing had a spell checker.)could I just splice in between the fan motor and the thermostat and if so, would this have any bad efect's ?
Any help would earn cudos.

[DmaxMaverick]

Pardon me. Just trying to visualize a "single blade electric fan" :D

To make your need easy, just install relays to engage the fan, one from the ECM, and one from your switch. With the relays, there will be no feedback to the ECM, and cleaner current to the fan. You really don't want "stray" voltage feeding back to the ECM.

It's a simple installation you could do yourself, or less than an hour's work for an electrician.

BTW:
What's the exchange rate for "cudos"?

Good luck

[AJ650]

Definately want to run the power through a switched relay rather than just through the switch. Unless you like having melted plastic dripping down your leg as you drive. No reason to tie into any other electronics, so there shouldn't be any problem there. 30 amp relays sell for around $5 at walmart/radio shack...

Wiring is simple, relay should have either 3 or 4 blades, depending on what you get. Run fused power straight from the battery to whichever blade is input, another line to pos on the fan. Connect relay to ground. Run fused power to an in-cab switch to the trigger on the relay. Flip the switch, power hits the relay and closes the circuit which then lets juice flow from the battery to the fan.

Relay packaging should have the basic diagram on it.

[RLAM]

Dura Dude:
Now that I come to think of it, A single bladed fan would be an Interesting consept. Must be the drugs. Oh well, I can't spell eather.

[RLAM]

Dura Dude:
Now that I come to think of it, A single bladed fan would be an Interesting consept. Must be the drugs. Oh well, I can't spell eather. Just for info, I got a reply from Journeydog and he has done this by putting a grounding switch on the coolant sender(i think, I have the info on paper and will half to read it again). He reports no melted plastic or unexplained smoke and sez it works great. I think I will try that if I can find the motor home. I think I left it in the yard someplace