Hi guy's, greeting from snowy Michigan! This has been my first winter with the Jr. Cummins up here and I've been very impressed! No problems at all starting in temps as low as 18 below (Not plugged in) she's impressed the other diesel owners at work aswell , they pretty much don't drive theirs in the winter,and when they do, they all plug them in .   

   Anyway back on topic- when I rolled into the cottage tonight and flipped off the lights , I noticed that when I had my foot on the brake , my right front turn signal was glowing dimly, let off brake light goes out. So I did a walk around and checked all the lights and everything but  a front side marker was working. Right turn signals worked correctly, BUT when I checked the left turn signals (with the headlights off) the right signal and brake light flashed along with it. When the headlights are on , everything seems to work properly..

  There haven't been any harness or wire mods that I know of, but the truck has been working in some downright nasty conditions for the last 2-3  months and this seems to scream bad ground, or a fault somewhere to me. Any problem areas I should look into first or is this something that might be a switch or board issue with the multi functin turn signal switch?  Sorry for the long post and thanks for any info you can share!

Edited February 8, 201411 yr by sngsht

Bad ground

Thanks- thats what I was thinking -  Thought I was posting in the Non - powertrain forum but I must have fat fingered my phone and slid it in here instead

I would lean toward a bad ground as well. I also have seen issues with the stock trailer wiring harness. It can get picky at times and even let voltage jump to other wires in the harness. It can cause some very weird problems. Try following the trailer harness and look for spots that are wore through. Also check the trailer plug on the back, they can short out internally.

Yep, I've had a couple of trailer couplers accumulate moisture. Upon inspection green corrosion bridging between wires or screws. I'd tear into the coupler before tracing any other wires. Take it off the mount and pull it apart and look for green crud. If you find some, I'd just replace it. They are like $10.

Thanks for the info guy's, I've been pulling a trailer quite a bit so the plug has definitely been open and exposed to quite a bit of salt/sand this year- I'll look there first  and work my way forward

Just wanted to give you a update, it was the flat 4 trailer connector. I had already taken the 7 pin apart and checked it (unfortunately it was -3 out, so locks on the connector snapped the minute I breathed on them ) since that's the only one I use, but it was clean so coated it with dialectric grease and put it back together. Pulled the flat 4 down out of the bumper ,pulled the cap off and was greeted with a sea of green corrosion- you could see where two pins had bridged together..Cleaned it up and greased it and alls well! Thanks for the help, that was a cheap fix!!

Excellent, those cheap / simple fixes are the best!!!