The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - My kingdom! My kingdom! My kingdom for an HEI module that will last

cleszkie · 07-09-2018, 06:22 PM

As mentioned above, high and low voltage will both kill modules. Running your keyed 12 volt source from your fuse panel is good, but not foolproof. That source can still experience fluctuations, depending on the condition of your trucks wiring harness. I recommend using the keyed 12 volt source from your fuse panel to operate a relay. The relay doesn't care about high or low voltage (extreme high voltage/amperage excepted). That way, you can run your clean 12 volt source directly to the HEI from the battery. I have found this to greatly increase the longevity of HEI modules.

07-09-2018, 06:22 PM	#20
cleszkie Registered User Join Date: Feb 2003 Location: Santa Ana, CA Posts: 2,191	Re: My kingdom! My kingdom! My kingdom for an HEI module that will last As mentioned above, high and low voltage will both kill modules. Running your keyed 12 volt source from your fuse panel is good, but not foolproof. That source can still experience fluctuations, depending on the condition of your trucks wiring harness. I recommend using the keyed 12 volt source from your fuse panel to operate a relay. The relay doesn't care about high or low voltage (extreme high voltage/amperage excepted). That way, you can run your clean 12 volt source directly to the HEI from the battery. I have found this to greatly increase the longevity of HEI modules.