Ok lately after I drive for a few minutes the overdrive light blinks. This is the light that would come on if you turn the overdrive off. It this blinking a transmission trouble code? Has anybody had this problem. The truck is an automatic and has no noticable problems shifting. I hope it is not serious because I use this truck to tow cars with my tow dolley.

 

What year is the truck and which motor? If its Later 96-98 you can check codes with a scanner, If earlier there is a way to get codes but you will need a manual. Does it blink all the time or only above 40mph?

 

The truck is a 1994 with a 3.0 so it is obd1. I know how to check for diognostic codes but I did not realize that it would tell me anything about the transmission.

 

I dont have the exact manual for that truck but you can get codes by doing this.
1. connect terminals TE1 and E1 on the diag connector (use jumper wire)
2. make sure O/D button is on.
3. Turn ignition on and count the blinks of the O/D off light, this is where the manual comes in handy because it tells you how to count blinks and what the codes are.
(the good news is if it is blinking a code it is most likely a solenoid or a speed sensor and not a mechanical problem)

 

Ok I think it will show the speed sensor code because my speedometer cable broke.

 

it did the same to me. it was the shift solenoid. any shifting issues? if so thats the culprit.

 

No problems shifting.

 

Are you sure the TE and E1 terminals aren't shorted together? Check that the diagnostics terminal isn't shorted...

Is the light flashing 2 times per second?

According to the FSM, if the O/D Off light flashes when the O/D switch is set to ON, the electronic control system is faulty.

 

.....

 

worth a look
http://www.ncttora.com/fsm/index.html

 

I checked under the hood and I didn't leave my usual paper clip under there. The light is not on all the time.

 

I would guess that either yer switch or wiring from the stalk switch may be bad. You could test it or disconnect it from harness to see...