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On my trailer I have brake lights, running lights, left and right turn signals...when the running lights are on and the brake is pressed, the lights go off. Only to come back on when the brake is released. Is this a grounding issue? Crossed wire? Something else? /forums/images/graemlins/confused.gif Need help fast as We are leaving this afternoon....

Thanks in advance. /forums/images/graemlins/thumb.gif

Do the brake lights work fine when the running lights are off?

Do all the running lights go off or just the tail lights when the brake pedal is pressed?

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Do the brake lights work fine when the running lights are off?

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Yes. Brakes work as normal when running lights are off.

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Do all the running lights go off or just the tail lights when the brake pedal is pressed?

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It is a small trailer, so the only light on it are the tail lights. But yes they go out completely.

Sounds like a grounding problem to me. At least that is what I would start with.

Check the wiring to the lights. Sounds like you have a crossed wire. The bulbs have a common ground. If you wired one of the power leads to the ground, you could see behavior like this. That's my best guess...

I will check this out. Thanks.

I just realized, I should have qualified that with "as long as you have it grounded". Sounds to me like your getting an intermittent ground through the switch in any case... The loop ground is not there when the switch is "on" so the lights go out when both are energized. Make sense?

It is def. a ground related problem.. Check your ground to the tow rig.

I have had this exact problem many times. It is the Ground. /forums/images/graemlins/thumb.gif

John

Just wanted to say thanks for all of the replys. I found the problem...the lights had lost a bulb /forums/images/graemlins/ignore.gif /forums/images/graemlins/blush.gif...I thought my dad checked that. OH WELL, just a reminder to check the obvious first.