I just bought the truck at an auction and went to drive it home and found out the speedometer and odometer didn't work. The abs/parking brake lights are always on as well. I found what I'm assuming is a speed sensor in the back of the transfer case, but it's a plastic gear that meshes w/ another plastic gear in the transfer case just ahead of where the rear driveline exits. The exterior piece has 2 wires coming from it. I'd only seen the magnetic type before. Anyway the end of the gear on the sensor is a little chewed up, so I'm hoping that's the problem. Question is, can I just replace the sensor gear, or do I have to replace the one in the transfer case as well? On the abs and parking brake lights, I pulled what I think is the abs sensor that was above the rear differential - it wasn't attached to anything though, just kind of hanging - it looks like someone had monkeyed w/ that area as the brake lines were held to the axle w/ zip ties! I'll get a new sensor and see if that fixes it, but if not any other ideas?

 

Maverick we have a few 90-92 dodge P/U's at work and the speedometer's quit working on them, we ended having to change out the speedometer assem. in the dash. Not saying this is your problem, but this is the problem we had. I think we have changed out 3 of them.

 

What year truck is it? That's helpful. Late model - 95 & up, the Speedometer is controlled by the rear wheel speed sensor. The sensor sits on the top of the pumpkin in the rear differential. It is a 14 & a 15 mm wrench you'll need to change it. There's a 90% chance that's all it is.

 

According to the thread title it's a 92.

I'd guess the speedo/odo problem is the chewed up gear. Try replacing the obvious one first, the hard to get to one if that doesn't work. Get somebody to hook an electric drill up to the speedo cable where the gear is and see if the speedo/odo works when that's spinning. If it doesn't, then you may have other issues.

 

My odomeyer hasn't worked since I bought it and my speedometer quits here and there on my 92 150 2wd.

 

Thanks Horatio, I hadn't even thought of trying a drill on it. I'll try that before I order the gear...no place in town has one in stock anyway, even the dealer!

 

The speedometer & odometer both worked with a drill turning the shaft - at least now I know the guauge itself is ok. Hopefully it will work w/ the new gear!

 

I'd say you need a new abs sensor on the top of the diff enless you can just plug the wires back in. also on the speed sensor i bet you didn't have od either?? thats a good inidication that the speed sensor is bad becuase thats the only way the computer knows that its going faster than 45 milesperhour to shift into Over drive. also if you don't want rear abs i'd just leave it unplugged and i've heard (dont' know) that it'll get rid of your traction controll

 

Sometimes the connector on the sensor goes bad from water corrosion. Check the connector real good and replace the sensor.

 

dodgedakotacrazy,

You're exactly right...OD doesn't work! I was wondering about that, I thought maybe the button on the dash was bad or something, but your explanation makes perfect sense. I'm still waiting on the new gear, I'll keep everyone updated on how it turns out.