2016 Forester MBS 2401s - LED Brake Light Will Not Turn Off

[kysunseekermbs]

I wanted to share the update on my tail light problem. Replacing the curt wiring harness resolved my problem, however I was confident the next time I drove in the rain I would have the same problem. My solution was to enclose the hardware in a pvc dual gang electrical box with a water tight cover. Note I had to use a box extender to get it all to fit but worked perfectly.

[kysunseekermbs]

Had trouble uploading the second pic in the same post.

[MNtraveler]

👍👍


Land of 10,000 Lakes
2016 Forester MBS 2401R

[cousin01]

That converter is usually used as an adapter for the trailer lights.

I am guessing that if you took it completely out of the circuit, the lights on the rig would all work correctly. Of course then your trailer connector would be inoperable so it would have to be fixed at some point.

Might be a quick fix on the road if part is not available.

[A32Deuce]

cousin. You are correct it is an adapter for trailer lights when the vehicle has separate circuits for each tail light function. FR is using the converter to mate the MD chassis with US style taillights.

[Pedrodasdas]

Hi Cousin, you and I have the same machine. Do we have that Curt converter ????

[cousin01]

I don't know but if we do it could explain the numerous failures reported of the auxiliary light control relay on the board above the tank valves.

I will look for it next week


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[cousin01]

Ped

I looked under the rig and we do not have the Curt controller. At least not there.

There is a wire bundle that goes from the 9 pin trailer light connector to the compartment containing the secondary taillight control board located in the utility compartment. I didn't open the panel to look for the Curt, but I don't remember seeing anything like it in there.

My guess is that the Curt is somehow being used to replace that failure prone tail light control board in newer versions.

[nusslejj]

Originally Posted by A32Deuce

cousin. You are correct it is an adapter for trailer lights when the vehicle has separate circuits for each tail light function. FR is using the converter to mate the MD chassis with US style taillights.

If someone has replaced the Curt - here is a question - does the Curt splice MB tail light wires, or does the Curt feed the tail lights

If it splices the MB wires on their way to the tail lights, then the Curt could be removed.


If it doesn't splice the wires, then perhaps because the tail lights are LED's, the Curt is required to drive them.

[Still Kickin]

Originally Posted by cousin01

Ped

I looked under the rig and we do not have the Curt controller. At least not there.

There is a wire bundle that goes from the 9 pin trailer light connector to the compartment containing the secondary taillight control board located in the utility compartment. I didn't open the panel to look for the Curt, but I don't remember seeing anything like it in there.

My guess is that the Curt is somehow being used to replace that failure prone tail light control board in newer versions.

I recall that FR switched to the Curt controller from the proprietary control board located in the Drive side sanitary compartment. There were numerous reportings of board failure, which probably had them go to the off the shelf Curt.

[A32Deuce]

Re-read post #45. That is why the controller is used. Either a control board or the Curt controller is used to mate the two.

[nusslejj]

What do you think about these two ideas --

1) Put the CURT module in a large ziplock bag while it is wired to the RV, then just fill the bag with spray foam. It should be completely sealed when it dries.
2) Lowes/Home Depot sell a 3" wide sticky-backed rubber tape used to seal windows/doors to new construction. When the tape touches itself it is completely stuck. You could 'wrap' the CURT with it and press it down around the outside/wires and it should effectively be waterproofed.

[dukeboone]

Originally Posted by nusslejj

What do you think about these two ideas --

1) Put the CURT module in a large ziplock bag while it is wired to the RV, then just fill the bag with spray foam. It should be completely sealed when it dries.
2) Lowes/Home Depot sell a 3" wide sticky-backed rubber tape used to seal windows/doors to new construction. When the tape touches itself it is completely stuck. You could 'wrap' the CURT with it and press it down around the outside/wires and it should effectively be waterproofed.

That's a creative approach that I suspect would work well. I've read elsewhere that the controller should not be fully enclosed to allow some air flow, nevertheless I wrapped mine up in a Ziploc prior to re-installing. I'm carrying a spare as well, so I figure I can test this "fully sealed" approach out with little risk of not having tail lights on a trip. Cheers!

[nusslejj]

Originally Posted by dukeboone

That's a creative approach that I suspect would work well. I've read elsewhere that the controller should not be fully enclosed to allow some air flow, nevertheless I wrapped mine up in a Ziploc prior to re-installing. I'm carrying a spare as well, so I figure I can test this "fully sealed" approach out with little risk of not having tail lights on a trip. Cheers!

I have not looked at mine yet, although I know it is in front of the back bumper. How much work is it to swap the CURT controller with another ? I'm guessing you have to re-do those two big gray connectors - which would take quite some time ?

I will be buying a spare from Amazon RSN, but may also have to buy the grey connectors depending on what you have to say !

Thanks !

[dukeboone]

I don't have enough of an understanding of what the controller does do know whether a different make or model of controller would be a worthy substitute. When I approached the repair on mine, I wanted to replace with the exact same module so I could verify my theory that it was indeed the source of the problem. Furthermore, I purchased the same connectors so I effectively wasn't modifying the RV since it's under warranty and at the time wasn't 100% certain swapping the controller would solve the problem. Worst case scenario I could have undone my repair and restored everything exactly the way it was and take it in for warranty service. The connectors themselves seem adequate for an exterior application and while the module is supposed to be installed in a protected location I suspect the missing gasket on one of my connectors might have created the problem to begin with. My 400 mile drive home from taking delivery at the dealer was complete with mountain driving and a deluge of rain, so all that moisture could have easily infiltrated the connector lacking the requisite gasket. HTH

[nusslejj]

Originally Posted by dukeboone

I don't have enough of an understanding of what the controller does do know whether a different make or model of controller would be a worthy substitute. When I approached the repair on mine, I wanted to replace with the exact same module so I could verify my theory that it was indeed the source of the problem. Furthermore, I purchased the same connectors so I effectively wasn't modifying the RV since it's under warranty and at the time wasn't 100% certain swapping the controller would solve the problem. Worst case scenario I could have undone my repair and restored everything exactly the way it was and take it in for warranty service. The connectors themselves seem adequate for an exterior application and while the module is supposed to be installed in a protected location I suspect the missing gasket on one of my connectors might have created the problem to begin with. My 400 mile drive home from taking delivery at the dealer was complete with mountain driving and a deluge of rain, so all that moisture could have easily infiltrated the connector lacking the requisite gasket. HTH

When I said "another" I should have said "a new one" - i.e., exactly the same model. I'm interested in the amount of work it took you to swap the existing CURT with a new CURT. If it has everything to do with the 4-pin and 6-pin connectors, then I suppose you could have a spare already wired ?

Thanks for the help,
Jeff N.

[dukeboone]

Originally Posted by nusslejj

When I said "another" I should have said "a new one" - i.e., exactly the same model. I'm interested in the amount of work it took you to swap the existing CURT with a new CURT. If it has everything to do with the 4-pin and 6-pin connectors, then I suppose you could have a spare already wired ?

Thanks for the help,
Jeff N.

Oh, OK. Sorry for the confusion. It was rather easy and I don't consider myself a wiring/electrical wizard. I did have the forethought to read the instructions for the connectors very closely and took my time to make sure I not only attached the connectors correctly but also matched up the wires correctly as it doesn't appear that it can be undone very easily if at all.

I simply cut the wires on the controller to the desired length (leaving some extra for margin of error), stripped the wire ends, placed the aluminum fittings on the wires and then inserted them into the plastic connectors. All in all it was probably a 15 minute job.

Cheers!

[nusslejj]

Originally Posted by dukeboone

Oh, OK. Sorry for the confusion. It was rather easy and I don't consider myself a wiring/electrical wizard. I did have the forethought to read the instructions for the connectors very closely and took my time to make sure I not only attached the connectors correctly but also matched up the wires correctly as it doesn't appear that it can be undone very easily if at all.

I simply cut the wires on the controller to the desired length (leaving some extra for margin of error), stripped the wire ends, placed the aluminum fittings on the wires and then inserted them into the plastic connectors. All in all it was probably a 15 minute job.

Cheers!

Those 4-wire and 6-wire plugs look like the wires have to be crimped - if so, did you purchase a crimper that works with them ?

Thanks !
Jeff N.

[dukeboone]

I have a wire multi-plier that has several crimping options but found it easiest to fold the two tabs over the wire with a set of needle nose pliers.

[kysunseekermbs]

When I replaced mine I used splice butts and did one wire at a time, it took about 20 minutes I would estimate. I put mine in a gray pvc box and drilled a couple holes at the bottom so that if moisture ever came into the box it would run out.

I do think the pvc box may have been over kill, the main thing is to stop the direct spray of water from the wheels. A ziploc bag that was suggested would be tough because there are three bundles of wires coming from two different directions. The black rubber sticky sheets you get in the home improvement stores would be good, I would put something in the center section like paper so the stick is just around the perimeter on the aluminum plate it is mounted to.

Update: We just drove 2000 miles to NYC, Washington DC and Philadelphia last week (half of it in rain) and the problem seems to be solved. Brake lights and running lights working as they should.