Strokemyaxe

Hello all. I'm about to wire up my dual electric fans. I'm looking for the best way to utilize what's already there. I will be using a temp sensor wired in line with the 12v switched to the relay. I also want to wire a a/c trigger/overide for my fans to always be on while a/c is on. Can I somehow use the leads for the old idle up solenoid for this? If so, how?

thanks,
Stroke

Patro46

Instead of using a pressure switch, you can use a trinary switch. This way you get intelligent control of your fans

Big2Bird

I wouldn't even try, and I am an electrician. Just add the wires you need to do it correctly. You can still hide them in the loom.

Strokemyaxe

Is this a major change to the air system? Where would I find the right switch?

More specifically, how would I install this switch on my factory a/c system?

-Stroke

69Vett

new fans are going to need large current capability, how much depends upon the fans selected, the idle solenoid wiring is not nearly capable of supplying the current you will need for dual fans.

Strokemyaxe

oh! I wasn't planning on POWERING the fans with it. I was planning on using it to trigger the relay that powers the fans. I know enough to know that using the solenoid leads for a power source would not be sufficient.

Where can I find a trinary shut off switch that is designed for factory system pressures?

7T1vette

If you are sure that this strategy will get the fans to do what is needed AND you know that the existing wiring supplies the 'trigger' voltage you need, there's no reason not to do so. A relay will absorb very little current draw from that existing line (which I am sure was capable of decent current going to the idle solenoid).

If the fuse on that idle solenoid circuit is appropriate for the addition of the fan relay, so be it. If not, put a separate fuse in-line to the relays.

Strokemyaxe

well.. heh... I'm not really SURE about anything. However, I'm fairly confident this will operate Ilas I intend it to. The relay is about 80 ohm so about .15 amps. I'm pretty sure the solenoid was more than that. One of my concerns is if there is anything further in the a/c that could be affected I guess. The other is if the idle Solenoid stayed on 100% of the time when the a/c was on. I think/hope it does. Like I said, NOT an electric guy at all.

Here is what I drew up and the diagrams I had to go by. If anyone can look it over and see any trouble spots, I sure would appreciate it.

BLUE1972

You can use the idle up wire to trip the relays as the relays take low amperage. You will have to trip the relays with a relay or the back feed will cause a short. Since the temperature sensors for a fan usually ground and trip the fan relay, the relay will have to supply a ground (when closed) to the fans relay trip wire.

I would tap into the 963 wire , use a separate relay to trip the fan relay and turn on the fan. I did on my 85 when I added a extra fan. I took the power from the low pressure switch - which only trips a relay that trips the fan relay which turns on the fan. The relay is only powered when the A/C is on. The fan power comes from the starter terminal to the fan relay.

That is what you show, it works.

Strokemyaxe

Perfect. Thanks for the confirmation. Hopefully I can get this done in the next few days. Once everything is confirmed working, I'm pulling the motor for prep of the stroker going in. Very excited.