sometimes when I have the CC set it will just start speeding up all on its own. The other day it went from 50 mph to wide open throttle and I shut it off at 70. I guess I should hook the scanner back up to it and watch the target speed there and the vss signal for starters. Can the potentiometer make this happen?

 

MOST DEFINITLY !!!
You have it turned past center - what the PCM thinks is center.
Don't know which way to tell you to turn it but mark where it is now and try about 30* one way.
If that doesn't work try 30* the other way.

 

ok thanks I will try that tomorrow

 

Mine did that with the stock TPS, till i put my gasser TPS on.

 

That fixed her thanks . This place is great someone always has the answer.

 

I am having a problem with the overdrive not engaging at all. Is there a quick fix to get it working? I replaced the wiring and hooked in a new sensor on top of the rear dif. The only thing missing on this truck is the rear proportioning valve. I bypassed it. It was way rusty. Brakes work fine and everything else seems to be fine as well. Vacuum is good. I had to jump the o.d. circuit as well. Are these two problems related? Is there a trick way to go around all the sensors and have cruise work? this was a cheap truck and I am on a tight budget. Throwing parts at it is not an option at this point. Thanks.

 

Well, replacing the sensor on the diff was a waste. It has nothing to do with OD.

What year truck? Does the speedo work?

 

yes, speedo works fine. No pulsing or bumping of the needle either. On a side note I have a water in fuel light on. When I push the valve in to drain the water it flows deisel. But it stays on. Any ideas? The sensor on the rear dif. is for what? Thanks guys, always a great source of info on this board. oh, it's a 91.5'

 

I belive the sensor on the rear is for abs

 

thanks, I read that in haynes last night. So back to my original question; Is there a way to override cruise? I am taking a long trip sunday and would love to use it. I am gonna mess with the fuel filter and see if I cant get that light to go out. thanks

 

There's ALWAYS a way

It's drastic, but it'll work....

Pull the 2 pin connector that controls the OD. Turn on your key and one side should be hot. The other pin is from the PCM. The PCM just puts a ground out there......

Has a light bulb gone off yet ???

Tap into the 2nd wire, run a wire up to the cab to a switch, run a ground to the other side of the switch. Presto - OD when you throw the switch on, no OD when you throw the switch off...
The trans should automatically drop out of OD when the trans shifts to 2nd when you're slowing down and will shift into OD AS SOON AS THE TRANS SHIFTS INTO 3RD..... so you'll want to turn OFF the switch either when you slow down to a reasonable speed - like 40 mph and turn it back on about the same or higher.
Then when you get back you can leave the switch OFF and continue trouble shooting the problem - but have OD available if you need to drive the truck somewhere...

 

no, no, I fixed the od already. I was refering to the cruise control. I was wondering if there was a way to override the cruise control. And possibly fix the water in fuel light. This was a cheap truck that I have been assembling from various parts. The body and frame came from the junkyard. Everything seemed to work save for the od and cruise control. Taking a trip sunday, hoping to have cruise. Thanks guys. I am sorry the very first thread should say Cruise control not overdrive. Sorry for the typo.

 

Dang, thanks a bunch for the help guys. I have also had this issue with my cruise. I didn't think of the potentometer which I had installed until reading this thread. Tonight, I took my pickup for a drive and did some adjustment to the pot. Now, the cruise seems to work great (knock on wood). Thanks again!

 

I understand the microswitches go out....
Don't have the wiring handy but they can be replaced with a switch also.

 

Thats what I am looking for. If anyone knows the way to wire a switch in to get the cruise working I would appreciate it. Thanks.