99 Cummins Guages wont work

[tuckerscummins]

I have a 99 Cummins that the tach and speedometer will not work, the overhead console is screwed up too on the miles to empty. I think they are both related because when it is raining they would work (they do not work at all now). It sounds like a ground issue but I am not sure where to check, does this sound familiar to anyone else?

 

[BudTX]

I'm with you on checking the ground first. I have no idea where the wiring for the dash gauges runs, though.

Hopefully one of our Dodge gurus will jump in with some insight.

Bud

 

[tuckerscummins]

Do you know where the ground is on the frame rail? We cross a low water crossing to get home and sometimes the water from it would make them work again.

 

[Cumminalong]

I don't think it is necessarily a ground issue on the frame. If that was the case, all of your electronics would be going screwy.

You said the water crossing sometimes makes it start working again?

I would check the electrical connection on your rear diff housing. The speed sensor is located there and is read off the tone ring in the diff.

Also, check the electrical connections on the driver side of the tranny, right near the tranny jack dog ear.

Both of those will affect your overhead display, as the computer doesn't know what's going on speed / RPM wise.

Lemme see if I have a few pics for ya.....

Here are the tranny connections on the driver side of the tranny....

Sorry, this is the best pic I have of the rear. The speed sensor connector is located on the front side of the housing, right near the top.

Pull them apart, clean and dry them and apply some dielectric grease to the connections.

 

[tuckerscummins]

When i get home tonight I will try both, I think we already replaced the rear diff sensor but I cant remember if that is the truck i was working on! Thank you for the help.

 

[tuckerscummins]

Well cumminalong............... I am all fixed!!!! I also used this sight to fix my 4th gear hunt.
I have been without guages and trying to find fourth gear for almost two years, I can't thank you guys enough for all the help. It was the speed sensor but didnt need replaced, the hard plastic line that has the two small red and white wires in it that runs to the sensor had been pinched btwn one of the bed brackets and the e brake cable and rubbed the wires in two inside the line. It probably took a total of 35 min to fix everything. Thank you again for the pics and thank everyone else on this site that helped out!

 

[DEERE3594]

Glad you got it figured out, welcome to DTR!

 

[tuckerscummins]

I love this, I am still trying to find my way around but this is GREAT!!!

 

[Cumminalong]

Glad it worked out for ya.

It's usually something simple on these things, but it's always something the folks don't think to look at.

Lemme know if ya ever need anything.