This is the first year plowing with my 94 2500, in the summer my speedo, does not work, (maybe once in a great while, it will bounce around) but I have notice since plowing season, the speedo will work most of the time. It may not work right from the get go, but after a few miles it will kick in, another thing, when it works, it will register the correct miles, but the mph, may be as much as twice. (and it may settle down and read the correct mph) I'm assuming its a moisture thing, but don't know what the moisture is getting to. Any ideas? thanks

 

Try a new sensor might be getting water into it. Check connector for water also and if rubber seal is there. Pull out the gear also and make sure it is ok, Take note at position the gear housing is so you put back at same spot. Put a little mopar silicone around o-ring since they always seem to leak there.

 

the speed sensor on the tranny it is a 2 wire plug on the back of the trans about half way up the trans on the drivers side that is probably loose in the plug and has a bad connection. Mine does this from time to time and all I do is crawl under the truck and fill the plug with dielectric grease plug it back in and it works. Considering that you get all the salt on the roads and that plug is kinda down where it gets sprayed by crud from the road that would be my first guess.

 

Thanks guys, I'll check it out.

 

Anyone else have the speedo and/or the trans lockup act up in wet or snowy weather?

 

I've had to beat the CAD unit with hammer in really cold weather to get it to engage. It's fun with a foot of snow on the ground.

 

What's the CAD unit?

 

Central Axle Disconnect. It's what engages the front axle so that you can have 4 wheel drive.

 

wheres that at? thanks

 

On the front axle, over towards the passenger side. There is a tube on the axle slightly bigger than the rest of the axle, and the CAD is attached to the back side of that. It has 4 bolts that hold it in, and a vacuum connector running to it.

This is the kit that I have on mine.
http://www.4x4posi-lok.com/app_dodge.html