I have replaced the speed sensor in my 91 d250 gas burner and my speedometer still isnt working, neither is the overdrive. Please help

 

Which sensor did you replace? (where was it?)

 

Speed sensor on the tranny

 

Well, that's the right one..... are you getting any codes for it?

May wanna verify it's getting its 5 volt feed from the PCM.

 

i don't think these have a 5v signal. just 2 wires. 1 is ground and the other goes to speedometer, pcm and DRL. if the speedo is not working and you have no overdrive i would assume you may have a bad ground or possibly a damaged wire somewhere between the sensor and the speedo and pcm. you can test things with a multi meter.

 

I do have 5v to the sensor. Yes it is only 2 wires

 

if the one has 5v to it then make sure the other one has a good ground. if thing still don't work there is a good chance something may be broken in the speedo head.