Taillights not working

[5 speed-FRF]

Headlights work. I took one tailight cover off, the bulbs contacts are rusted. I did check the socket and I am getting 11.43 volts on both. Is that enough? Tried to sand the contacts but they dont work. The sockets look good though so Im hopeful. The screws were very tight. Feel like they have never been off. 2015 Thor Vegas. Also where are the fuseblock for the chassis besides the one under the hood? Econoline owners manual shows another regular in cabin one too; does that exist?

 

[16ACE27]

Axix/Vegas/ACE (among others) taillights are a known problem area for water intrusion. Behind and below the enclosure hole you may find wire splices that are problematic.

Is it just the taillights? What about brakes. turn signals, reverse? If none work it could be a ground issue.

 

[5 speed-FRF]

None work back there i see the hole you speak of and some splicing with those clip on connectors but all the wiring looks good. Thw wire loom under the coach near the trailer receiver was just hanging down and I zip tied it up as best I could so it wasnt just hanging pulling on connections. I could have caused the issue I suppose but I was careful not to pull or strain the wires. They are all still in their looms and the wires themselves look good. The coach wiring looks good everywhere ai have looked so its a bit puzzling.

 

[16ACE27]

I 'm betting on a poor connection on a common ground wire.

 

[5 speed-FRF]

Would it show the 11.43 volts if the ground was bad? Ill get bulbs tomorrow and try them

 

[16ACE27]

Would it show the 11.43 volts if the ground was bad? Ill get bulbs tomorrow and try them

depends on how you measured it:

If you removed the bulb and measured the no load voltage at 11.43 VDC (which is pretty low) between the + side and - side of the bulb connections you could still have a poor connection. If you can measure the voltage with the bulb installed and read 0 VDC that would pretty much confirm it.

 

[ghnl]

Try measuring the voltage to a known good ground (a jumper cable to bare metal on the chassis for example). If the voltage is now closer to battery voltage you know it's likely a bad ground.

I had some non-working rear clearance lights in our prior Class C motorhome. I took off the back panel in the bedroom closet to find the ground wires were ganged up under a screw head - the screw went through some plywood and then into the (aluminum?) frame of the back wall. It did not provide a secure ground path. And a few inches away the metal (aluminum) frame was accessible which made for a more secure ground connection.

 

[5 speed-FRF]

I may also run a new ground wire just to be sure while its apart

 

[5 speed-FRF]

As it turned out I did need bulbs as they were so rusted. It was also I believe moving wires around and a ground issue. Seems to be good now. License plate light still not working. I plugged my magnetic tow lights in and verified they work and threw then in the hold so if needed and theres a problem I can throw them on to get me home

 

[5 speed-FRF]

Lights are still working fine as a follow up. I also used RB pro sealant around the lens where they meet the body hopefully to keep it from leaking any further and ruining the new bulbs. I also purchased an LED license plate bracket and installed that all good.