I've been having this on going problem with my overdrive not engaging. By this I mean my car is stuck in gears 1-3, it won't go past 3rd. I've re-soldered the overdrive relay. The relay was fixed and works like a charm now, but it didn't fix my initial problem. So, I did some more research on these boards and found that it might be a wire. I checked the wires for current and they all worked. There were no signs of physical damage to them either. So, I got a new OD solenoid and the tranny was still stuck in 1-3. I took out the new solenoid to return it, since that wasn't the problem, and put back in my original solenoid. Now for the breakthrough- My OD is working now, but only on warm days like 55+ degrees farenheight. And now that I think of it... It was around last Novemeber that it started to fail. And it was on and off like it is now. So, cold weather is assisting my problem. What do you guys think it is?