Best way to wire up Aux fan.

[elkabong]

I have an 84 without an Aux fan. Living in the land of blistering summer time heat I decided to acquire an aux fan from eBay. I just received it. My question is what is the best way to wire it up. I was thinking of just putting a switch inside and only turning it on when needed.

Are there other options and is there anything I need to worry about other than, finding a power source and wiring it to a switch? I did get the relay with it but without the relay socket I am not sure what good it will do other than isolate it from evething else.

Thanks in advance.

 

[rrubel]

If you do a search on the forum, I asked the identical question about a year ago and a couple people gave very detailed instructions for wiring it in with a relay and an underdash switch. I also got mine from eBay, and got the relay socket from a junkyard. Switch came from Walmart.
[RICHR]

 

[geekinavette]

Jim,

If you want your aux. fan to turn on in parallel with the stock fan...

The relay should have (at least) four connections; two for the switch contacts, a coil positive and a coil negative. You can tap off of the existing relay for all but one wire, the one that goes to the fan (red w/ black on existing relay). On the existing relay the large red wire is battery power to the switch, blue is ignition power to the coil positive, and tan (I think, maybe brown) to the coil negative (this is the one that goes to the temp switch and AC pressure switch). Then just run the other switch contact to your aux. fan.

If you're interested I can send you a diagram of the adjustable controller I'm using in mine. I like it because the difference between on and off is only a few degrees, not 15 degrees like the "on at 200 off at 185" switch, and I can adjust the turn-on temp to wherever I want it.

Bill

 

[elkabong]

rrubel - thanks. I think I found what you suggested.

Bill - The diagram would be great.

I also have started working on the HAM 7747 ECM conversion. So far no issues. The directions on your website have been great. I'll let you know how it goes. The Prominator thingy sounds pretty slick as well. It will be nice to finally have time to mess with the ECM. ;-)

Thanks

 

[geekinavette]

Here ya go Jim:

http://misterbill.homeip.net/vette/fan_controller_schematic_3_0.pdf

Just shoot me an Email if you have questions.

Let me know how that HAM install goes, so far I haven't had any complaints yet. Yes the Prominator is going to make tuning so much easier. We're still about 6 weeks away from a production run of those.

Bill