Problem with trailer lights

[Reynolds]

I am having some problems with the lights on my dad's snowmobile trailer again. I have brake lights and turn signals, but I have no running lights. Where do I start? Could it be in fuse in my truck?

[Jeremy airjer W]

Could be. Start by checking for power to the running lights at the connector on the truck side. If no power than it could be a fuse if there is power than there is likely a bad connection at the plug or a broken wire in the trailer harness!