1 tail light only works when running lights are 'off'

[71safari]

Our 1 tail light will only work (for turn & brake signals) when we have the running lights off....any ideas as to how to fix would be greatly appreciated! We're stumped.

[Lumatic]

It sounds like crossed wires. Have you had this trailer and TV a while? What is your TV? Was the light working OK before? Are you sure the trailer 7 way (umbilibcal) wire configuration match the TV. New 7 ways are pretty much standard but unless it has been changed, the wiring configuration on your 71 will not match all the wires with a newer TV. Hook up a 12v lead and ground and when try powering the turn signal connection at the 7 way. If it then lights your umbilical is probably cross wired. If so you can rewire at the access panel behind the front gaucho.

[funkill]

So, when running lights are on, both tail lights work?

Laura

[richinny]

check the ground at the light.

[moosetags]

First off, welcome to the Forums. We're glad to have you with us.

Regarding your tail light woes, the first thing that I would do is check the bulb on the errant light. Sometimes dual filament bulbs can become finicky. The bight element may not want to light when the dim element is lit. Try a brand new bulb, any see if it acts any differently.

Brian

[71safari]

wow - that was quick - thanks for all the help!
this trailer is new (to us) - just completed our 'maiden voyage' last week
when our running lights are on the problem light won't signal (the other side always works), we've swapped good for bad bulbs & didn't work... I'm going to get my Dad & husband to check out the crossed wire suggestion & I'll let you know what they find

[garry]

Take off the lens and check the ground connection for the bulb socket sometimes with a bad ground (rust) the bulb will get ground through another bulb.

Garry

[Minno]

Corrosion in or around the bulb socket can cause a grounding and/or lighting problem as well.

Chris

[arodriguez60]

I agree check for rust or corrosion. sounds like a bad ground. Most problems on 12 volt systems are the ground