Trailer Brakes Work on Some Trailers But Not Others When Towing with 2008 Chevrolet Duramax Dually

Updated 06/20/2025 | Published 05/09/2014

Question:

I have a 08 Chevy d-max dually, my brakes work fine on my toy hauler 40er. But I hooked up to a flat bed trailer and they didnt work but the brakes lights do. The flat bed trailer does wk, on a different truck tho, now Im haveing the same problem on this stacker trailer. All works good on the diesel pusher. But not on my truck. But a little dump trailer brakes and my toy box brakes work fine. When you plug in my Tk, it tells you trailer connected but its not saying that with these two other trailers. Again both of these trailers work on other trucks. I did not play with it to much to try to figure it out because I was in a hurry. Any help. Thanks

asked by: John F

Helpful Expert Reply:

This is an unusual issue that you have come across. The first thing I would look for is corrosion on the trailer connector pins. If there is corrosion build up, that can affect the connection between a trailer and different trucks, especially if you do not usually pull those trailers with that truck. Corrosion, dirt or grime can build up on the pins and trucks that consistently pull a specific trailer can develop wear spots that keep the connection, but a new trailer connector may not have as good of a connection.

I would also check the ground connections for the trailer connector and the trailer brakes on all of the trailers. If the trailer you are having problems with has rusted or corroded ground connections, it may be possible that those grounds are too weak for your truck to pick up. If the trailers ground through the hitch ball, make sure there is not too much rust or grease preventing a good ground connection to the hitch ball. Also make sure there is a good connection between the connector on the trailer and the socket on your truck.

Do all of the trailers have electric brakes or is it possible that some of the trailers have electric-over-hydraulic brakes? I can tell you that the GM factory integrated brake controller is not compatible with electric-over-hydraulic brake systems, so this may be one possible issue.

If you are not able to come up with the problem or a solution after trying these steps, let me know what you come up with and we can take some further steps. Keep in mind, the functionality of the brake lights is not related to the functionality of the trailer brakes. Trailer brakes and brake lights run on two different circuits on a trailer.

expert reply by: John H

Cody B.

11/24/2024

I drive a 2008 Chevy Silverado 2500hd 6.0 liter gas truck and I am having the same issue. I just purchased a used trailer and completely replaced the wiring with brand new everything. My father drives a 2017 Power Wagon and has no issues with the brakes where my 2008 Chevy doesn't even recognize there is a trailer. All other trailers I have pulled have been just fine with brakes and works flawless. Any ideas?

Willie

6/20/2025

Are electric over hydraulic brakes compatible with Ford or dodge?

Jerred H.

6/20/2025

@Willie Yes, but it depends on whether or not your brake controller has an electric over hydraulic setting. What model brake controller do you have? If it's a factory brake controller what year, make, and model is your truck?