Two Electric Fans controlled by the Sniper.

[Whordell]

I’m running two Spal Electric fans with my Be Cool setup on my '70 Charger 440. I was looking to hook my A/C up to the Sniper also. I found this pic on the Vintage Air website. My question is since I want both fans coming on the same time, can I wire both green and blue wires from the relay (water temp sensors), and then just one wire to one of the Sniper outputs, or do I need to run each wire separately from both relays into their own output wire?

[Chris805]

The way I wired my fans was with a three relay setup from a LS Tahoe/Camaro. This way both fans come on at low speed and as temperature increases they switch to high speed. From my understanding the low speed fans get less then 12V, and high speed gives the fans a full 12V. This setup is easier on the charging system as well as the fan motors because you aren't pulling full speed at fan startup or running the fans on high until you really need to. There are ready-made harnesses with the three relays and fuses if you shop around.

[a b c]

You can use one output to control both relays.

[Danny Cabral]

Yes, exactly. https://forums.holley.com/showthread...916#post211916 (Related Forum Post)

[Whordell]

Me being a non-electrical type of guy, it’s sometimes hard for me to wrap my ahead around all of this. My two Spal fans are 11” that’s a little over 2700 CFM. I can’t remember exactly what relays Be Cool sent me to use. I went through all of that thread you sent me. So if my relays don’t have a diode in them, the diode I’m going to put inline for my A/C should be good enough to protect everything? And if not, should I change out relays or…? And you also said you wanted full cooling for your A/C. Does that mean you have your fans ON when the A/C is engaged, not controlled by by temperature? You also said in the setup to choose Ground or +12V. I’m assuming the labeled temperature sensor wires going to the Sniper are basically just grounds.

[Danny Cabral]

So if my relays don’t have a diode in them, the diode I’m going to put inline for my A/C should be good enough to protect everything? And if not, should I change out relays or…?

Installing the diode(s) is fine, but it's just easier to use diode protected relays. See section # 6: https://forums.holley.com/showthread...Fan-Holley-EFI (Wiring An Electric Cooling Fan - Holley EFI)

And you also said you wanted full cooling for your A/C. Does that mean you have your fans ON when the A/C is engaged, not controlled by by temperature?

Yes, my dual 12" electric fans turn on automatically whenever the A/C is on. See section # 2 & # 8: https://forums.holley.com/showthread...Fan-Holley-EFI (Wiring An Electric Cooling Fan - Holley EFI)

You also said in the setup to choose Ground or +12V. I’m assuming the labeled temperature sensor wires going to the Sniper are basically just grounds.

I don't have the Sniper EFI, so use whatever Sniper EFI software option you have.

[Whordell]

Installing the diode(s) is fine, but it's just easier to use diode protected relays.

OK, thanks so much! I’ve got everything figured out except with the diode. So my relays and everything is already mounted and wired up as I previously was running a carburetor setup. If a diode will protect my EFI just as good, it would save me from rewiring it. So my question is, will the one diode I’m installing for the A/C be good enough, since I’m going to be tying both grounds together off of each relay then going into one output? Or will I need to install a diode on each ground coming off of my relays and then another one for my A/C?

[Whordell]

I think the diode thing may have went way over my head. Are you saying that I can buy two diode protected relays, and just unplug the two that I have, and plug the diode protected relays right in?

[Danny Cabral]

Yes, simply replace your two existing relays with two diode protected relays.

[Whordell]

Thanks again Danny!