how to turn both fans on with radiator fan?

[gorf]

I want my AC fan to turn on at the same time as my radiator fan. There are a ton of question about controlling them with a switch:

http://www.dsmtuners.com/forums/new...-issue-plus-wiring-them-up.html#post151319397

Looking at the link above, it looks like it is a simple matter of jumping pin one of the radiator fan to pin one of the ac fan.


My concern is am I going to burn the ecu by supply a ground on the ac circuit to turn on the fan?

Should I use pin one on the high relay and tie it to pin one of the ac high relay?

 

[draculia]

The fan power/ground wires don't go back to the ecu, they go back to the relays. Use a multimeter to be sure you're jumping the right wires. I hate the stock fan wiring, 5 relays for two fans high circuit doesn't kick on till over 220 degrees, it's nuts.

If your modlist is up to date, might want to look into upgrading from your safc to a 98/99 ecu with ecuflash and ceddymods. In addition to the much more precise fuel control you'll have, you also have complete control over the fan circuits. For instance, my low circuit is never tripped since they're set to 300 degrees, high circuit is tripped for both fans at 200 degrees. Now I have 3 extra relays in the fusebox, one will be for my water/air IC pump and another for my water/air heat exchanger fans.

 

[gorf]

The fan power/ground wires don't go back to the ecu, they go back to the relays. Use a multimeter to be sure you're jumping the right wires. I hate the stock fan wiring, 5 relays for two fans high circuit doesn't kick on till over 220 degrees, it's nuts.

Thanks, what I had in mind, was taking a piece of wire and slipping it in the hole for pin one on the relay, and jumping it over to pin one on the other relay. Pin one of the relay is on the ecu side and the reason I was worried about frying the ecu.

If your modlist is up to date, might want to look into upgrading from your safc to a 98/99 ecu with ecuflash and ceddymods. In addition to the much more precise fuel control you'll have, you also have complete control over the fan circuits. For instance, my low circuit is never tripped since they're set to 300 degrees, high circuit is tripped for both fans at 200 degrees. Now I have 3 extra relays in the fusebox, one will be for my water/air IC pump and another for my water/air heat exchanger fans.

I have read some of the threads and considered the 98/99 ecu. But just like always, I am fighting another problem now. maybe after that is resolved I look into it. Your solution for fans certainly sounds like the best idea.

 

[MrBoxx]

I used this write-up from the VFAQ site when I did my cooling fan override. I also used a switch, but it will work even if you just jump the relays to each other. The diagrams in this write-up should help you.

 

[gorf]

Very interesting
Here is what I had in mind looking at the relay base there are four prongs two horizontal and two vertical. The bottom left vertical is pin one. According to the link I supplied in my first post. If you take pin one to ground, the fans turn on. I tested it and that is the case, but the engine has to be running.

I also tested my idea by jumping them and then taking it to ground, both fans turn on. I was thinking using the low radiator relay to turn on the high AC relay.

I guess I'll just have to test it. pin one on low radiator relay goes to pin 21 on ecu, AC high relay pin 23 goes to ecu. I guess if the ECU is only supplying ground to turn on the fans then simply turning on ground with another relay "should" not burn the ecu???????


Edit took out my drawing because it lost formatting