Sorry for bringing this up again, but I spent all weekend under the car and so maybe a new perspective will help.

By the way, I am Joe Anglim, and always have been...

I replaced my OD relay several years back (before word reached me of this magician named Don) and all was well until recently. About 6 weeks ago the car started refusing to engage the OD, even though the relay audibly clicked and the light lit and unlit. Saturday I took out the solenoid and couldn't get any sound out of it by applying 12V (and it's wiring was looking bad right up to the cap) so I replaced it with a new solenoid and good wiring. Now I get a click at the relay and under the car, and ovedrive does engage, but I can't get it to drop out of OD into 3rd by pressing the button. IOW, at 60mph on the highway, with the light off / overdrive engaged, I push the button and the light comes on, but nothing else changes. The transmission seems to be shifting well otherwise and it has fresh mobil 1 atf in it.

Seems to me like less of a problem than the OD that won't engage, but something obviously isn't right.

Any thoughts?

Thanks,

Joe

Joe, check to see if the voltage to the solenoid drops ( at the wire going to the solenoid, with it disconnected from) down when you press the button to take it out of OD. My 740 was cutting the voltage in half from approx 14V when I pressed the button. I guess that's how the system works. My problem ended up being the relay.