I'm losing my mind with this car. The overdrive was kaput when I got the car, so I did a bit of debugging and settled on the "cut the channel in the solenoid" option for a spare solenoid I had for my AW71. I can still get the relay to click and the OD Cluster light to come on with the solenoid unplugged. That tells me it's a short in the wiring based on what I've read on this forum. Somewhere that circuit is finding a ground (probably in the shifter) and giving a ground path for everything. This has gone on for about a year. OD is behaving nicely and kickdown works just fine. Just no manual activation of the passing gear. Well, this evening I got ambitious and decided to debug the lack of a switchable overdrive once and for all.

Pulled the console out completely (good time to replace all those burnt out bulbs in the shifter anyway). Wiring is FLAWLESS and not even dusty! Looks like it just came out of the factory. So I started tracing the thing back. Unplugged the OD solenoid connection after it comes back into the shifter from the outside (nice convenient 2-pin plug there). Would you believe the light still works, relay still clicks, the whole bit? Ungh??

Okay, that shouldn't be happening. Get out my voltmeter and check at this little 2-pin. +12 and 0 exactly when and where one would expect, switched by the button. How's that possible? I thought the ground path was through the solenoid body for the whole circuit, including the light! Okay, get a couple of jumper wires and check with a "real" solenoid. WTF? It works as it should! I'm thoroughly confused now. Did they change something on the 88's?

When I mount the solenoid on the transmission, it doesn't work. At all. Lights and relay play nicely, but the solenoid doesn't do its magic like it did in the testing. Check the passage...it's clear. Blow it out to be sure. No change in operation once reinstalled. Put the channeled solenoid back on, and the OD is functional again. Grrrrrrr.

What the heck am I missing here? Is there some voodoo you gotta do on the solenoid when installing it? I'm fairly certain it's not dirt getting into the holes. The +12 is making it all the way to the connector on the underside of the car just fine. It just doesn't make sense!

Thank you!