Need help with brake lights and running lights

[Happy Camper 5]

Over the weekend we apparently had a wiring short in our trailer, which has now unfortunately caused us to lose our rear lights (running lights, brake lights, turn signals, hazard flashers) on our 2017 2401W Forester. I have checked all the fuses that we could find and coming up with nothing. Any suggestions?

[mTn_biKer65]

I just went through something similar. Passenger side tail light and electric brakes weren't working. My suggestion would be find and clean the trailer grounds. There should be one up front on the frame and some near the wheels on the frame as well. My other suggestion would be check/clean the connections for the 7-way plug on both the truck and trailer. In our case this was the fix. I squeezed the connections on the trailer end back tight again and spread the connections on the truck as best I could. 8 hours and 4 trips later the problem hasn't returned.

[Happy Camper 5]

Thanks for the suggestion, I'll definitely check the grounds. I heard a pop noise when everything went dead. I'm still thinking there's a fuse located somewhere in the motorhome that I'm not finding.

[Bama Rambler]

A couple of questions because I don't have experience with that motorhome.

1. Does that unit have the Curt light controller?
2. Does the Curt controller still have the known issues in the 2017 units?
3. Have you checked the fuses in the underhood fuse box?

[DaveJordan]

This is related to the Hopkins trailer light controller. The MBS chassis can't drive the trailer lights directly, so FR uses a Hopkins controller installed behind the rear bumper, near the 7 way plug. They used to use a Curt controller but had problems and ended up recalling the Curt and replacing it with a Hopkins model.

When they replaced my Curt, the new controller came with two inline fuses installed in wire runs. One was installed with the controller itself, in the wiring behind the bumper. The second was installed in the wiring under the driver's seat, where many of the MBS electrical components are installed. There may be a third fuse, installed in a socket under the seat.

My guess, and it's only a guess, is motorhomes built with the Hopkins controller may have different fusing - the inline fuse under the seat might be in a socket. So I'd start by looking for an inline fuse in the controller wiring by the back bumper. I'd then look for an inline fuse under the driver's seat - if neither of those work, you may have to remove the driver's seat (being very careful about it's attached wire) to get access to the MBS fuses.

One other approach might be to run a 12 volt line directly to the controller - maybe through the inline fuse (if you've got one) to ensure that the controller itself hasn't been fried.

Perhaps someone who knows the wiring on the new units could chime in? Well, perhaps not...

Good luck!

Dave

PS - There's been a lot of discussion about the trailer lights. Do a search for "Curt Controller"

[Happy Camper 5]

You are correct about the Hopkins controller, I did see that mounted on the coach behind the forward of the bumper area. And yes it does have an inline fuse (20amp) which I checked and it was good. I didn't know about the one under the seat. I'll have to look for that. Thanks for the suggestion about running 12v directly through the fuse on the controller. I'll try that when I get home from work today. Thanks for everyone's help on this!

[PenJoe]

Originally Posted by Happy Camper 5

Over the weekend we apparently had a wiring short in our trailer, which has now unfortunately caused us to lose our rear lights (running lights, brake lights, turn signals, hazard flashers) on our 2017 2401W Forester. I have checked all the fuses that we could find and coming up with nothing. Any suggestions?

Great floor plan on the 2401W! It's unusual to lose the hazards, brake lights, turn signals, and running lights at the same time. The most common cause would be a ground, but a ground does not cause a popping noise. A bad ground just causes an incomplete circuit to everything it is responsible to. Can you explain further as to how the wiring short occurred? In other words, could all of the wires have been pulled loose? Do the 2401W lights work? What were the circumstances when you heard the pop-driving, inside/outside of TV, turning, connecting, location of the pop?

Several years ago the trailer wiring harnesses were serviced from the same wires and fuses as the TV. For safety reasons, newer vehicles all of the wiring to the trailer wiring harness on separate circuits that are fused under the hood. So if, for instance, the tail lights are working on the TV, but not the trailer, look for a separate fuse in the under-hood fuse block.But unless all of the circuits came together in one short, it is not likely all of the fuses would blow at once. Or it could be the module mentioned above.

[DaveJordan]

Originally Posted by Happy Camper 5

Thanks for the suggestion about running 12v directly through the fuse on the controller

Actually...as I thought about it some more...

Since you've found the inline fuse at the bumper, you can test that with a multimeter, or an auto 12 volt light-on-a-probe gizmo, to see if it's got 12 volts With the ignition on, it should be seeing power.

Dave

[DouglasReid]

Originally Posted by mTn_biKer65

I just went through something similar. Passenger side tail light and electric brakes weren't working. My suggestion would be find and clean the trailer grounds. There should be one up front on the frame and some near the wheels on the frame as well. My other suggestion would be check/clean the connections for the 7-way plug on both the truck and trailer. In our case this was the fix. I squeezed the connections on the trailer end back tight again and spread the connections on the truck as best I could. 8 hours and 4 trips later the problem hasn't returned.

I had a similar issue with the 7 pin connector in the bed of my truck for connecting my 5er. If I used the connector on the bumper everything worked perfectly. If I plugged into the connector in the bed nothing happened. After a thorough cleaning with contact cleaner and chasing the oxidation with a very small file and emery cloth the bed connector works perfectly.

[Happy Camper 5]

Update - yesterday evening I once again checked the in line fuse near the rear bumper with a multimeter and it was definitely dead. So based upon everyone's suggestions I searched up stream and found the inline fuse under the drivers seat which was blown. I did have to remove the drivers seat to gain access to it, and it was inside a red cover marked with a 15amp sticker. Everything is now working once again.

A big thank you goes out to everyone who helped and a special thanks to DaveJordan and Kyle from Forester River! This forum has helped me out numerous times!

[Mr. Dan]

... and we appreciate your coming back to post your solution/results. That helps us with similar problems in the future.

[Beachsailor]

When you pull the drivers seat make sure you get the seatbelt sensor wire put back correctly. The tech who did the recall work on our 2016 2401w did not and the first time I rotated the seat it was damaged. 250 dollars later at the BM dealer it was fixed.

[MNtraveler]

Thanks for the follow up. How many times have we heard that someone checked a fuse OK and when they went back and checked it again it was bad? Those buggers sometimes look awfully good when they are bad. A continuity test can verify if a visual is unclear.