2015 Tiffin Phaeton No Brake Lights on 7 pin connector

[Pullirs]

I just recently purchased a 2015 Tiffin Phaeton 40QBH. I purchased a new tow bar and installed on my 2010 Honda CRV.
Hooked up the car to the MH and the tail lights, running lights & turn signals are working but have no brake lights. Installed a Roadmaster brake relay kit on the Honda and still no brake lights. Plugged the new tow bar electrical connector to my 7 pin connector on my truck and to the Honda CRV and all lights worked including the brake lights so I know the tow bar electrical connections are working.

The MH lights are all working correctly so finally checked the 7 pin connector on the motorhome and have no brake light power on the 7 pin plug or at the connector that plugs into it. Have checked all the fuses and connections but no luck. Called Tiffin & Freightliner help line and Freightliner said I would need to take it to the nearest dealer to have it checked out. Freightliner was suppose to email me electrical schematics but need to call them again because I didn't receive.

Does anybody have any ideas what the issue may be? Thanks for anyone's help in advance.

[Lt Dan]

Did you check the fuses and relays in the passenger side rear compartments? There is a fuse and relay block there for the turn signals. Also, there should be a converter in the light wiring lines that changes the brake/turn signals from separate lights on the coach to combined for the toad. The diodes in the converters have been known to fail.

[FIRE UP]

Originally Posted by Pullirs

I just recently purchased a 2015 Tiffin Phaeton 40QBH. I purchased a new tow bar and installed on my 2010 Honda CRV.
Hooked up the car to the MH and the tail lights, running lights & turn signals are working but have no brake lights. Installed a Roadmaster brake relay kit on the Honda and still no brake lights. Plugged the new tow bar electrical connector to my 7 pin connector on my truck and to the Honda CRV and all lights worked including the brake lights so I know the tow bar electrical connections are working.

The MH lights are all working correctly so finally checked the 7 pin connector on the motorhome and have no brake light power on the 7 pin plug or at the connector that plugs into it. Have checked all the fuses and connections but no luck. Called Tiffin & Freightliner help line and Freightliner said I would need to take it to the nearest dealer to have it checked out. Freightliner was suppose to email me electrical schematics but need to call them again because I didn't receive.

Does anybody have any ideas what the issue may be? Thanks for anyone's help in advance.

Well Sir,
Let me ask you, do you have "Amber" turn signals on your coach? Or, are they RED as normal? You see, if you have amber ones, then somewhere in your wiring before your 7 - pin connector on the back of the coach, is a 3-wire to a 2-wire tail light converter. It will take the signals from your amber turn signals, both of them, and put them in that little black box. It will also take your brake light signal from the coach, and put it in there too.

On the output side of that little black box will be only two wires. A right turn/brake, and a left turn/brake. And both of those wires will enter the back side of the 7-pin plug. Now, if you DON'T have amber tail lights, you WILL NOT have the 3-wire to 2-wire tail light converter. You wiring will go directly from the tail lights through a set of fuses and, to the 7-pin connector.

So, when doing your testing of that plug, are you getting a left and right turn signal from the coach, on the two different pins assigned to those signals? If so, those same pins will also go solid when the brakes are applied. But, being on a Freightliner chassis, you also have a totally separate set of fuses for the 7 - pin plug. You say you've "checked all the fuses and no luck", correct? Did you find the fuses for the 7-pin connector, not the ones for the actual tail lights on the coach?
Scott

[luvlabs]

Passenger side last three compartments, you will find fuse box for all of the taillights and trailer connector. Exact compartment depends somewhat on the model. If you find the chassis batteries, you have the right compartment.

[Pullirs]

Lt Dan,

Appreciate the quick response. I have located the trailer lights for the 7 pin connector in the rear compartment. All fuses and relays are good. I didn't find the convertor wiring or the diodes? I attached a photo of the trailer fuse/relay compartment. Maybe you can review to see if there's something I'm missing. I'm thinking I may have a bad trailer light harness but why would it only be the brake lights not working.

Thanks for your help!

[Pullirs]

Fire Up,

No Amber lights only Red. I have located the trailer lights compartment but still not able to identify the issue!

Thank You for the quick reply!

[MSHappyCampers]

Hi ! Welcome to IRV2! We're sure glad you joined the gang!

Congrats on the new rig! Wish I could help with the light problem. Keep her between the ditches!

Good luck, happy trails, and God bless!

[Lt Dan]

Scott (FireUp) explained the wiring very well where separate turn signals and brakes on your coach are combined. What you are looking for is something similar to the photo below where the separate signals are combined into a common brake/turn signal light.

[l1v3fr33ord1]

A reminder: Many coaches come with turn signal switches that have two sets of contacts. One set is turn-signal only, and the other is turn/stop. For those coaches, no converter is needed. I would expect this to be the case for almost every coach manufactured after 2010, including the OP's 2015, as well as some from 2005 onward.

[Jake21]

Originally Posted by Lt Dan

Scott (FireUp) explained the wiring very well where separate turn signals and brakes on your coach are combined. What you are looking for is something similar to the photo below where the separate signals are combined into a common brake/turn signal light.

Yep. I would check the wiring here. My splitter failed and I lost my toad lights.