Originally Posted by Cab_Burge
I bought two of the Standard brand replacement ECU, a 4 wire and a 5 wire, from my local NAPA store. I wasn't sure which one was better so I will try both and see which one I like the best luck


The only difference is that the 5 pin is exactly the same as the 4 pin but with a dummy 5th pin so people wouldn't complain that it didn't have 5 pins like the original did.

Improved design did away with the basing resistor (the extra two prongs on a 4 prong ballast) that the 5th pin was used for.