I have an 89 ram 2wd 150 w/ 318/tbi and what appears to be the a904 or a999. I'm assuming a999 because from what I've read the 904 didn't have a locking converter, which mine does (did). It stopped locking up about 2-3 weeks ago, right around the time I changed passenger side motor mount, which should be irrelevant. Can anyone give me some tips on what to look for to troubleshoot this? Is there a wiring harness I can bypass to manually lock to determine if converter is bad or something else? Thanks in advance.

 

Did you check for codes? If you have a lock-up converter, you should have a (PTU) part throttle unlock solenoid that should set a code if bad.

 

No, I haven't. In fact I'm pretty sure there's no bulb in that light, which means I'll have to undo the dash to put a bulb in. Then it's the usual on off on off on to get codes right?

 

You got it.

 

Got a code 34, speed control shorted or open. I guess if that tells the speed to the tranny that makes sense?

 

If that's the sensor down where the speedo cable is on the tranny, wonder if I crunched a wire when I raised the engine against the firewall/floor to change the motor mount?

 

I went under the truck to look at the sensor and noticed it was very loose in the trans. I tightened it up, disconnected and re-connected battery after about 5 minutes, and took it for a ride. Now the converter is locking up pretty consistently around 47 under normal acceleration. Not bad, but it used to hook up before 45, around 42-43. And I'm still getting the code 34. Only thing I haven't been able to do is examine the actual wiring from the engine bay to the plug to see if there's any damage there. So it's closer but not quite there.

 

mabe the code 34 is still showing up because the computer did not reset when you disconnected the battery.

 

I guess it's possible, maybe didn't leave it disconnected for long enough. But it is locking up, just not as soon as it used to.

 

Were you at operating temp? Low temp will effect lock-up speed.