What is this?

[Brian Duhart]

So I just inherited a 2007 2500 Cummings slt and I’m trying to figure out what I’ve got and how it works. I’m going to tow a 31 ft fifth wheel with it. Anyhow I’m trying to figure out what this little box on the shifter is and how to use it.... any ideas???? It’s labeled Cummings

 

[MADDOG]

Welcome to the forum.

Interesting device and it has a Cummins logo to boot. Not sure what that is. Have you tried operating it yet?

OBTW, what is a "Cummings" ?

 

[HemiLonestar]

OBTW, what is a "Cummings" ?

Beat me to it lol

What's it do when you pull the knob?

 

[G-Ride990]

That's an exhaust brake. Check out this video, he shows it in use.

 

[Smokeybear01]

You will really appreciate that little knob when you're on a long grade with trailer in tow.

 

[Brian Duhart]

Thanks folks... you some of you got me, i meant cummins, I just didnt know yet. I have only towed with this once and I did try to pull the knob but I did not feel, see or hear anything different. The little LED light came on. I did not want to mess with it again until I found out what it did.... Maybe I just did not know what to look for.... this is my first diesel.

The unit in the video is exactly what I have but I have an automatic transmission. Thanks again everyone, this saved me a trip to a diesel mechanic or something to try to figure it out... I have a nearby hill with a prefect grade to test this thing out... Will it only work if I am towing?

 

[Sandevino]

Will it only work if I am towing?

Nope, buy you want to make sure your seatbelt’s tight if you’re unloaded.

 

[Smokeybear01]

And DON'T step on the accelerator at the same time-you'll create a conflict.