Trailer brake not working

[1LargeCar]

I did some searches but nothing close to answering my question. Does a 2008 Caribbean have one or two brake light switches. Reason for asking is that my coach brake lights work fine but nothing goes to the trailer. I have turn signals on the trailer and running lights just no brake lights. Seems odd that the turn signals work but the brake lights don't. Monday I'll do a harness strip down to see just what is going on as far as wire health.

I get all the odd ball stuff, I'm just blessed that way.

Thanks
LC

[Old-Biscuit]

Do you have a Brake Controller installed?

Do you have a 4 pin or 7 pin connector for trailer?

[1LargeCar]

No brake controller, 7 pin.

Title should have read "brake LIGHTS"

Sometimes I think my disability is more mental than physical.

I have stripped back part of the harness and found wires that were cut then reconnected using a jumper wire right back to the cut. Real odd, might have had something to do with the previous owners dingy towing. I'm in the process of fixing that wire bypass. Any word on two brake light switches. Maybe that also has to do with the dingy tow. A mystery.

Thanks for the reply Old-Biscuit.

LC

[1LargeCar]

Look what I found under the drivers floor. Looks like a brake valve with two switches. Looking very closely it looks like the bottom switch has two wires that loop up onto the top switches posts then two wires run off to the brake lights. If that is true failure of one switch would not effect the operation of any brake lights. I do not have a brake apply pressure gauge so I don't think they could be switches for gauges.

What say y'all.

LC

[twinboat]

Switchs are in parallel because it's a dual braking system. If one air system fails, you still have brake lights. It's not your problem.

Does your rig have combined stop/signal lights or separate stop and signal lights ?

If separate, you'll need a converter for your trailer.

There will also be a separate fuse for the trailer brake lights. That's so even if they short, you will have RV brake lights.

[1LargeCar]

I think I have a handle on the problem. I do have amber turn/emergency, red stop and tail lights. The coaches lights work now that I did a proper repair on the hacked wiring harness (possible pre owner hack) and the trailer light are correct. So I think I need the doohickey that twinboat is talking about. Etrailer?

Thanks all

LC

[twinboat]

Etrailer, UHaul, Amazon, just Google trailer light converter.

[LETMGROW]

Originally Posted by twinboat

Etrailer, UHaul, Amazon, just Google trailer light converter.

Or most any local auto parts store.

[1LargeCar]

Does nobody offer a 7 blade to 7 blade converter that can just be plugged into the motorhome then plug the trailer into that. Seems like an easy thing to do. Or am I missing something?

LC

[l1v3fr33ord1]

LC-

I'm not sure your coach would have a converter. According to the 2009 brochure (link here), Freightliner built the chassis. Typically, a model-year 2008 Freightliner would have all the signals it needs at the hitch connector, without a converter. The fact it has a 7-pin connector is usually a sign that there's no converter.

I suggest the missing brake signals could be due to:

1) A failed trailer brake fuse/relay. You can find the Freightliner fuse boxes anywhere, but mostly they are towards the rear end of the chassis, on the driver side. A call to Freightliner with your chassis VIN might give you an idea of where to find the trailer hitch fuse/relay box(es).

2) Or, a failed turn signal switch. The brake signal goes into the turn signal switch, which does the combining for the trailer hitch signals. If that part has failed, you'll get turn signals at the hitch connector, but no brake signal.

[1LargeCar]

Originally Posted by l1v3fr33ord1

LC-

I'm not sure your coach would have a converter. According to the 2009 brochure (link here), Freightliner built the chassis. Typically, a model-year 2008 Freightliner would have all the signals it needs at the hitch connector, without a converter. The fact it has a 7-pin connector is usually a sign that there's no converter.

I suggest the missing brake signals could be due to:

1) A failed trailer brake fuse/relay. You can find the Freightliner fuse boxes anywhere, but mostly they are towards the rear end of the chassis, on the driver side. A call to Freightliner with your chassis VIN might give you an idea of where to find the trailer hitch fuse/relay box(es).

2) Or, a failed turn signal switch. The brake signal goes into the turn signal switch, which does the combining for the trailer hitch signals. If that part has failed, you'll get turn signals at the hitch connector, but no brake signal.

Oh joy, more stuff to check out, but good stuff. With trusty multi meter in hand I'll go check these possible solutions.

Thanks

LC

[THenne1713]

You do not mention and signature does not list your rig, but some Fords had multiple fire safety recalls on Brake switch leaks/ shorts/ wiring harness fuse errors, affecting Cruise, so your photo showing potential brake fluid switch leaks is concerning. Good Luck p.s. 7-pin TESTER maybe good investment to determine whether TOW or TOAD issue?



https://www.amazon.com/s?k=7-pin+aut...ref=nb_sb_noss

[1LargeCar]

Originally Posted by THenne1713

You do not mention and signature does not list your rig, but some Fords had multiple fire safety recalls on Brake switch leaks/ shorts/ wiring harness fuse errors, affecting Cruise, so your photo showing potential brake fluid switch leaks is concerning. Good Luck p.s. 7-pin TESTER maybe good investment to determine whether TOW or TOAD issue?



https://www.amazon.com/s?k=7-pin+aut...ref=nb_sb_noss

Thanks for the post. Freightliner chassis with air brakes so I don't think I have an issue. 7 pin tester is a good idea thought.

LC

[1LargeCar]

The rest of the story. Bought the tester as suggested and plug it into the 7 blade connector on the motorhome and everything is working fine. Brake lights and turn signals all doing whet they are supposed to do. I guess the problem was the hack job the previous owner did in wiring up his towed vehicle. After the harness repair that I did alls seems to be well. Thanks for all the help/

LC