Tail light woes

As a much younger man, I got the name tag that said "Trailer Service Manager" only because I could sleuth out the bad ground problems endemic to trailer lights.

Excuse the short clarification here, but are you getting the same results from two different tow vehicles or from two different trailers...
It reads as you have the same situation with two different trailers..

Trailers should be wired so that the tail and marker lights all come on with the tow vehicles parking lights. If that is not what you are getting, the use a test light to probe the trailer connection in the tow vehicle.

Matt

Does the trailer have side clearance lights? And do they work?

What truck do you have. The tail lights may have a dedicated fuse. Get an inexpensive plug in tester to plug into the truck connector.

Get yourself an outlet tester (They make them for the tow light socket on a Tow vehicle) and see if the tow vehicle is outputting tail light.
If not.. There may be a fuse just for the TRAILER in addition to the one for the tow vehicle's own tail lights.

As I understand the OP his Tioga running tail lights don't work, nothing to do with any trailer.

With the lights on remove one bulb, is it OK? Any corrosion on the connector? Use a voltmeter grounded to a good frame ground for 12V and check for 12V. If OK then the problem is a ground wire or connection problem. If not OK check for voltage at the head light switch to help isolate the problem. The problem can be wiring, connectors, fuse, CB, relay or switch.

CA Traveler wrote:
As I understand the OP his Tioga running tail lights don't work, nothing to do with any trailer.
…….. .

You are correct. Sounds like a problem with his Tioga class C MH. I got side tracked by his mention of a trailer.

First thing I would look for is a dedicated taillight fuse if the clearance lights are also not working.

Older Fleetwoods had a few glass fuse holders for the rear lighting usually accessed up the back wall from the outside looking up by the drivers side. Between the bottom of the rear wall up about 12 inches. Doug

If the fuses all check out it could also be the headlight switch itself. There's one contact for clearance & tail lights and another for headlights. This is how you have the first position for just "parking lights". If that contact has failed you won't get any lights.

Does the dash cluster light up? Those are usually on the same circuit to be an indicator that you have no tail lights.