So.. after putting in the replacement engine, and putting the front clip back on.. and realizing how simple the wiring harness is..... I ran into an issue.
So, the side markers on the corners (not the park/turn signals up front) run through the major/minor of the parking/turn circuit. The side parking lights ARE NOT GROUNDED...except through the turn signal filament....which is now LED.. so it's not getting ground through there...
BUT, the driver side works normal, the passenger side had the turn signal on high and the side marker super dim.. So, where else would the side marker get a ground path from?
So, I spent hours chasing grounds... checking voltage and resistance at different points, and knew the LEDs were an issue. They are literally diodes, so they block voltage in direction, thus not allowing the return ground path through the filament that doesn't exist in LED but does exist in conventional bulbs. BUT.. as mentioned, the driver side worked fine...the circuits are identical for right and left sides, so it makes ZERO sense that the passenger side didn't work... So I literally followed the circuit... all the way through.. and.. realized the turn signal bulb in the cluster was out.... and there was my ground path that it wasn't getting... replaced the bulb, and it's all working...
Having redone the wiring for the engine, I also noticed my Gen2 light wasn't on...but it worked before I parked it over a year ago...and I just replaced the Gen2 bulb shortly before that...I Spent hours tracing that circuit, testing relay, etc.. I finally get to the Gen2 bulb socket in the cluster...and the socket and connections test good.... so I'm at a loss at this point....
I had just replaced the bulb in the turn signal indicator, and figured I had a couple spares so I might as well replace it while I have it off, even though I just replaced it... and... waddya know.... came right on.....
A good 6-8 hours of troubleshooting, over 2, 39 cent light bulbs....
GM engineers.... what were they thinking?
