Brake lights

[Ken&LouB]

Our two lower brake lights and blinkers went out...extra one above middle still works. 2018 Jayco Seneca 37K

[Robbbyr]

Originally Posted by Ken&LouB

Our two lower brake lights and blinkers went out...extra one above middle still works. 2018 Jayco Seneca 37K

If you turn on a blinker do you hear a relay "clicking" under the driver's seat? The Freightliner system tells that module under the seat to operate the lights when you step on the brakes or operate a signal.

Do the front turn signals work when you operate a blinker?

[Robbbyr]

Attached is the newest Freightliner Body Builder Guide that explains the SmartPlex (multiplexed) electrical system on our units. Obviously electrical systems in newer vehicles are not like they used to be!

As someone else stated (on Facebook) a bad ground can be the sole cause, several owners of newer Senecas have discovered poor grounds in the rear which might be all your issue amounts to.