The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Depinned engine harness --- now ... ??

e015475 · 03-18-2019, 06:10 PM

If you are running two fans, you can use the 3-relay setup to run the fans at half speed most of the time and full speed when there's big demand on the cooling system.

If you only have one fan and it is noisier than you'd like, consider a PWM variable speed control.

If the fan noise really doesn't bother you, just hook the fan (or fans) to a 50A relay and ground it with the PCM to run the fan at 100% (this is what I'm doing - I have a 16" SPAL fan in a shroud. The noise would have to bother me quite a bit to part with $165!)

03-18-2019, 06:10 PM	#16
e015475 Registered User Join Date: Nov 2013 Location: Show Low, Arizona Posts: 759	Re: Depinned engine harness --- now ... ?? If you are running two fans, you can use the 3-relay setup to run the fans at half speed most of the time and full speed when there's big demand on the cooling system. If you only have one fan and it is noisier than you'd like, consider a PWM variable speed control. If the fan noise really doesn't bother you, just hook the fan (or fans) to a 50A relay and ground it with the PCM to run the fan at 100% (this is what I'm doing - I have a 16" SPAL fan in a shroud. The noise would have to bother me quite a bit to part with $165!)