Why are these lights continuously on and flickering?

T800 is a completely different cab. T660 doors shut a lot like the T600/T800/W900. The T680 has huge pass-through vents on the rear sleeper wall and built-in air leaks in the doors, so the doors shut more like nice pickup truck doors. Unfortunately, the built-in air leaks ensure your left arm and leg stay frozen, all winter long. There’s no excuse for the poor build quality of the T680.

 

I was just saying might help close the door. I’m aware of the differences between the cabs.

 

truck is haunted.

 

Those lights have three wires running to them. Ground, contant hot for the small light, and a switched hot for the large light. I built a set of water Mellon lights for my truck to replace those lights.

OP: a few years ago I had a 680 that those lights would flicker and eventually just come on with no way to turn them off. Eventually I just had to unhook them.

 

And, the ground wire is switched by the BCM, because it’s a CAN bus system, which is why the positive wire is always hot, and why you couldn’t turn off the T680’s lights.

 

The switch must be broken on my ground then. Both lights ground through the housings. the switched power wire powers the red light and the constant power wire runs the clear light. Both are run on a three position switch that is bright-off-dim. The red light comes on with the door switch and the door lights, like the factory lights

 

my last truck had the same lighting issues. The dome lights would go on and off while I was driving. I thought the truck just took on some hitch hiking ghosts. The shop had nooo clue what to do with the issue.

 

I got thrown into a 680 yesterday while my truck was down. The whole #### truck flickered. Including the transmission. It wound up on a hook. lol.