The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - LS Swap

TooTall · 04-11-2019, 04:12 PM

When you say single speed only, did you mean both on via PCM trigger? If that's the case, then they'll both come on at the same time with 2 relays

If you want them to operate independently, you can have fan 1 come on at high temp, and the other with the A/C trigger.

The best way would to have both fans operate on 2 speeds via the PCM triggered grounds from the PCM:

This can be done with 3 relays. They will function on low and high speed with PCM triggers

04-11-2019, 04:12 PM	#2
TooTall Registered User Join Date: Mar 2009 Location: League City,TX Posts: 66	Re: LS Swap - dual fan wiring When you say single speed only, did you mean both on via PCM trigger? If that's the case, then they'll both come on at the same time with 2 relays If you want them to operate independently, you can have fan 1 come on at high temp, and the other with the A/C trigger. The best way would to have both fans operate on 2 speeds via the PCM triggered grounds from the PCM: This can be done with 3 relays. They will function on low and high speed with PCM triggers __________________ 1973 K5, full vert, 6" BDS lift, 35 Mickey T MTs 1984 K10, 8" lift on 35s 2004 3/4 4wd, 33s Toyo Mts, Long Tube headers, 3K multidisk 80e, tons of miles 2011 Yukon XL \| Bone stock 2013 Audi Q5