No running lights, help!

[Champ2005]

Alright, I hooked my trailer up and had no running lights. I have brake lights, turn signals, trouble lights work, but no running lights. It's a 7 way plug (dual axle trailer). I used someone else's plug and then had nothing! Why would I have no running lights? And, why would I get nothing from someone else's plug that works for their, but not on my boat? I thought at the very least I'd get the same thing from his plug, so I was surprised when I had nothing. Help! Thanks!

[billnorman1]

Not sure exactly what the 7 pin swap was all about, but you need 12 volts on the brown wire of the 4 or 5 pin flat connector to your trailer. Since your brake lights work, that pretty much rules out a ground (white wire) problem, they use more current. The brown wire should be the first one next to the white (ground) wire, and on the 7 pin socket, the first wire counter-clockwise from the keyway.

[Champ2005]

I was just trying to see if it was my plug that was bad. My flat pin connector goes into the larger, round plug-in connector (7 pin?). I figured maybe mine was bad, but then his didn't work at all. Anyway, so you're saying make sure I'm getting 12volts to the brown wire?

[Texas Larry]

Your truck probably has a separate fuses for all of the trailer tail lights. Look in the owners manual and locate and check the fuse for trailer tail lights.

You should see 12V on pin 3 on the connector on the vehicle with the lights on.

[Champ2005]

Found the problem. A 15amp fuse was blown in the truck. RV store said if it blows again, you probably have a ground issue. Its my wifes suburban and had never used it to tow before, so Im hoping the 15amp was blown prior so I dont have to chase a ground issue.

[CatFan]

Found the problem. A 15amp fuse was blown in the truck. RV store said if it blows again, you probably have a ground issue. Its my wifes suburban and had never used it to tow before, so Im hoping the 15amp was blown prior so I dont have to chase a ground issue.

They couldn't be more wrong. A ground issue won't ever blow a fuse. Likely what you have is an area of insulation rubbed through on one of the brown wires on some trailer you have pulled. It's also possible that somehow the plug shorted it out some time while hooking up the trailer. Carry extra fuses with you.

[Champ2005]

Exactly what I did CatFan. I have extra fuses just in case. We'll see when I tow it tomorrow. Thanks guys!

[MasterCASTER!]

Found the problem. A 15amp fuse was blown in the truck. RV store said if it blows again, you probably have a ground issue. Its my wifes suburban and had never used it to tow before, so Im hoping the 15amp was blown prior so I dont have to chase a ground issue.

I had the exact same problem.....damn near had to have myself committed trying to track down the reason why. I went over that damn trailer top to bottom, front to back.......before I had a stroke of genius and decided to look at the fuse in my truck. Yep, blown.

[Champ2005]

I just got home yesterday after 12 hours of driving, four of which were at night, and all was fine. Lights worked great. I'll keep my fingers crossed that it continues to work, so I don't have to chase down any trailer issues.