Short history; overdrive was shifting erratically most days working well some days, but slowly got worse untill there was no delay at all between third & fourth. Now it doesn't matter what speed the third shift happens it shifts into od imediately. Also it won't downshift into second untill I'm under 5mph. I have installed the pot fix but no change. I have 0-5 volts through the pot switch Any help??

 

It sounds like you have the pot adjusted wrong.

 

The trans shifted this way with the pot unplugged as well, also forgot to mention that the od switch has no effect either. The light works but will not cutout the od. Have adjusted the pot all over the place to no avail. I cannot keep the od from shifting immed after the third gear shift. No other probs ie; a/c speedo alt

 

Check for a short to ground from the OD solenoid then. Unplug the solenoid and check for ground on the wire that isn't blue.

The OD lockout is a "dummy" switch, it just tells the PCM what you'd prefer then the PCM does what it was going to do anyway.

 

would a short to ground have the od engaged through all three shifts?? cause it doesn't come in till after third. Tryin to wrap my head around this od thing, thx for the help Wanna

 

The hydraulic system keeps it from going into OD until you hit 3rd, then you get that stacked shift.

It could also be shorted inside the trans, or the solenoid valve could be stuck open.

 

Ok will checked for shorts, but how do I check for valve probs??

 

If you don't have a short in the external wiring, check for a short to ground on either pin on the solenoid.

If it's not the external wiring you will probably be replacing the solenoid anyhow. It's pretty cheap.