Here's not how to spend an afternoon in 100 degree heat.

The OD on my manual '88 745t was working fine last time I drove the car a week ago. Yesterday, dead as a hammer.

Pulled the ashtray, checked the repair I'd made to the switch wiring three years ago, fine. Pulled the relay and checked the solder repair I made two years ago, also fine but I sweated all the joints again anyway. Still no go.

(BTW, you can troubleshoot this with the key on, engine off, trans in 4th and press the button on and off while in the relative comfort of your driveway.)

Hmmm. When I pulled the trans out for a new clutch in '03 the wiring passing through the tunnel was shot and had lost all it's insulation so I'd made a new harness. Car up on ramps I slithered my sweaty 270lbs under to check all the wiring and hide in the shade for awhile. All good but still no worky.

I pulled the relay tray out, removed the OD socket and confirmed all the contacts were there and good, to no avail.

I was about to accept I now had a 4-speed brick when I absent-mindedly (general theme for the afternoon) pulled fuse #12 and saw it had blasted apart internally.

Four hours and a new 15 amp fuse and life is good again.

Doh!

Erwin in Memphis.. for now.