Trailer lights dim Kenworth T600

Check the truck side of the trailer plug. This time of yesr they will get severely corroded. I worked on a fleet of 50 T600s, first place I would check.

 

I have seen bad ground wires cause that exact problem. Either the large white wire is not making connection or the 5th wheel ground cable is broken. Since the problem persists with different cables and trailers Im betting you will find the bad connection in the tractor.

 

We don't run ground cables from the 5th wheel. Not necessary.

Simple test. Run a piece of wire from the frame of the trailer to the frame of the tractor. It will spark when you find conductivity and the trailer lights will be bright.

Purely a ground issue.

Most of the time when this happens, taking a flat blade screwdriver and slightly spreading the prongs on the female 7 way connectors on tractor and trailer alleviate the problem. If that doesn't work, investigate using a different cord. Sometimes, the ground wires inside can fail.

Sorry to say, I think the repair shop ripped you off.

 

I agree, and I know you're trying to put it mildly.
I'm sure both you & I know there was no question the shop knowingly ripped him off.
If the trailer lights lit up at all, even dim or flickering when he brought it in, that shop knows #### well it wasn't a fuse, let alone an $80 one with $76 labor to install it.
I'd be putting at least $140 worth of hurt on that "mechanic" right about now.

 

He said hes already tried different cords and another trailer. The ground strap is useful when the contacts on the cord are a little corroded.

 

Then I would hone in on the tractor 7 way and check the integrity of the ground circuit. I'm not going to subscribe to having a ground strap in lieu of properly maintaining electrical connections. If they are a "little corroded", then they should be cleaned and/or replaced and preventative measures taken to assure they don't "corrode again". I use this on all my connections and it saves me in the winter months. I run twin 48's and there is a lot of opportunity for electrical failure. And everything grounds through the 7 way.

I'd love to know the name of the repair service. We could all make a call and tell them to stop ripping off the unsuspecting. "Mechanic" indeed.

 

I never said "in leiu of" did I?. Id rather not get caught at a scale because something goes wrong on the road or I happened to hook to a trailer where somebody didnt bother to maintain tbe ground wire.

 

You could round the next corner and get flagged down for a roadside inspection too. Never know where dot may be.

 

Exactly. Always pays to be prepared

 

No, you did not. My response was based on the fact that I hook only to trailers that are maintained internally, even if I go out in the system and pull ones not dedicated to our operation. I suppose if I were say, a container hauler, I may look at it differently. However, when I used to do that 25+ years ago, I tired of the fact that they didn't bother to fix the brakes and put good tires on them either.