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

dwcsr · 02-03-2014, 10:46 PM

You need to connect a relay in there. You can't connect direct from the PCM to the fan.

The blue fan wire needs to be connected to a relay #87 terminal. The 30 term to the battery. The 86 tem to the green PCM wire the for engine cooling. You would use the PCM blue wire if you had a second fan or a 2 speed fan.

02-03-2014, 10:46 PM	#2
dwcsr Hollister Road Co. Join Date: Apr 2005 Location: Houston Posts: 6,134	Re: LS swap cooling fans You need to connect a relay in there. You can't connect direct from the PCM to the fan. The blue fan wire needs to be connected to a relay #87 terminal. The 30 term to the battery. The 86 tem to the green PCM wire the for engine cooling. You would use the PCM blue wire if you had a second fan or a 2 speed fan.