I have 1991 W-250. 5.9, auto. The overdrive is hit ormiss. If I drive about 20 minutes over 55 mph it sometimes comes back. I have tested the tps and its fine. The trans fluid is good. I replaced the temp sensor with a new one and totally lost od. I put the old one back in and it is once again hit or miss. Some one said to ground the od solenoid. How?


1991 W-250

 

I don't know diddly about the autos, mines a stick, so can't help you there. I do recall seeing some discussion of manually switching the overdrive with a toggle switch, you might try a search. The smart guys will be back tommorrow, they're all down at tbolings whooping it up today, so hang loose and someone will be along.