I measured it on the blue wire coming out of the alt and going to the ECM, I traced it up to the top of the engine, the wires join in a plastic box under the engine cover. I Was torn whether or not to replace the alt or the VR, I guess the safest option is to just replace the alt, I think I'm looking at $500 on eBay unless anyone knows of a cheaper option? I'll report back once it's fitted-now off to remove the alt, this should be fun!