Lost trailer brakes and brake lights

[JKellis]

Hi everybody, I could use some advice. I pulled off the interstate and turned on my flashers. When I merged back on, my turn signals were not working. I turned the flasher switch on and off several times and the turn signals started working again. Now the flashers don't work, I have no brake lights, and no trailer brake. I still have power to the controller. Any help would be appreciated. Thanks

 

[DavidC]

Are the truck lights working, not counting the RV.

 

[JKellis]

Are the truck lights working, not counting the RV.

The truck and trailer running lights work. I have replaced the stop light and flasher fuses and the trailer relay nothing changed.

 

[JKellis]

The truck and trailer running lights work. I have replaced the stop light and flasher fuses and the trailer relay nothing changed.

No brake lights on truck or trailer

 

[DavidC]

Checked fuse 5 in PDC under hood ?

 

[JKellis]

Checked fuse 5 in PDC under hood ?

View attachment 126264

The fuses in my PDC do not have numbers that I can find. There are only three 20 amp fuses in the PDC which are ECM, stop lamp, and hazard. Stop lamp and hazard are new fuses.

 

[Timd32]

Yeah that fuse 5 and the brake light switch are the only two things (besides wiring) that run the Center High Mounted Lights. Back of cab.

So if you have nothing at all not even those.

Fuse first, the the brake light switch.

Would say if you have the center highs and no rears that looks to run thru the turn signal/hazard multi switch. Maybe it's hung up inbetween hazard and normal?

 

[JKellis]

Yeah that fuse 5 and the brake light switch are the only two things (besides wiring) that run the Center High Mounted Lights. Back of cab.

So if you have nothing at all not even those.

Fuse first, the the brake light switch.

Would say if you have the center highs and no rears that looks to run thru the turn signal/hazard multi switch. Maybe it's hung up inbetween hazard and normal?

I have no brake light on the back of the cab either, but to be honest I'm not sure that light ever worked, I've never checked it. At this point I'm thinking of making the trip home like it is. I have running lights and turn signals truck and trailer. The trailer is empty and only about 3000 lbs so trailer brake is not really necessary.

 

[DavidC]

Bad ground G100 ?

 

[JKellis]

Bad ground G100 ?
View attachment 126266

Possibly, Ill check

 

[DavidC]

Seem's crazy but it shows G100 under Drivers side Battery ?

 

[JKellis]

Seem's crazy but it shows G100 under Drivers side Battery ?

View attachment 126267

At this point, nothing about the electrical system on a gen2 would surprise me LOL

 

[DavidC]

Does your rear fender, license plate lights work, seems I think going through this that they use the same ground. May help narrow it down, I haven't looked at the multi function switch as Tim referred to.

 

[DavidC]

Hang on, here it comes

 

[JKellis]

Does your rear fender, license plate lights work, seems I think going through this that they use the same ground. May help narrow it down, I haven't looked at the multi function switch as Tim referred to.

I have fender and license plate lights. It's down to no brake lights or emergency flashers, and no trailer brake. The trailer brake controller powers up when I connect the trailer to the seven pin plug, but the brake does not engage when I brake.

 

[DavidC]

As far as brakes, have someone activate the brakes (slider etc.) and check pins 2 and 1 with test light. That should come directly from the controller or have a ground connection at the plug.

 

[Timd32]

Good info on those diagrams.

I pulled off the interstate and turned on my flashers.

This is why I thought it would be related to the Hazard turn signal switch. Thats a main part of the stop lights. If that is not changing over properly nothing seems to work.

Looks like turns, hazards, stop are all using same bulbs.

The hazards don't use the brake switch but just in case here is the stop light switch connector.

 

[Ozymandias]

Does it work with the trailer disconnected and after cycling the ignition?

Sometimes the BCM cuts down circuits if something is out of specific parameters.

 

[NIsaacs]

The fuses in my PDC do not have numbers that I can find. There are only three 20 amp fuses in the PDC which are ECM, stop lamp, and hazard. Stop lamp and hazard are new fuses.

Did you check the fuses in the cab fuse box? The brake controller is activated by your brake lights, so if no brake lights no trailer brakes.

 

[JKellis]

Did you check the fuses in the cab fuse box? The brake controller is activated by your brake lights, so if no brake lights no trailer brakes.

I checked all the fuses and all were good. I drove it home in the daylight and flipped on my lights when I hit the brakes to let the person behind me know I was slowing/stopping. No problem getting home. I am waiting on it to warm up before I get out and look for the problem. Thanks everybody for your help. I will post an update when I figure out what's wrong.