Quote Originally Posted by gotaflat View Post
yep ok understand,

Thats for the car right - is the trailer plug a separate feed/plug? straight from the CJB (according the diagram)? Because that red line has 0.0v (may be an initial 0.02v) but zippo - i cant explain that - i am sure that needs to have a signal (can potentially run a wire with diode to the car brake light.. but ....)

I can only speculate that there may be crossed /exposed wires down to the rear 6 pin round socket? that why the car thinks there is a trailer on once the trailer brake (blue to Brown trailer wire) is joined??
Does it behave the same with the brake controller connected?

Yeah I just checked they both come from the JB separate, I was wrong, thought they were joined at rear.

Check fuseable link 18.

Need to see if the trailer lights work, but that would only be the red wire anyway.

I'd check all the breakers attached to the cjb. But if work has been done in the rear. I'm going there first