I don't kn ow what CJB is. I don't get any voltage out at the rear connectors, eithere the 7 pin or 4 pin straight connector. If I use the right turn position, the corresponding fuse shows the voltage pulsing as it should when the flasher pulses. On the left position, the fuse shows a constant voltage and does not pulse.
How can you check the yellow wire out of the fuse panel? I have checked the yellow wire back at the rear harness and nothing there. How does it get constant voltage and not pulse? Does it count on the load to cause the pulsing? Since the truck left turn signal flashes, is there a second flasher or circuit for just the left turn signal to the trailer?
How does the truck left turn signal work and how is it connected differently than the trailer circuit. Does the truck left turn signal also go through the CJB or straight to the truck light directly. If the truck left turn signal works then the flasher is working so how does it require a differently load on the trailer wiring?
If it flashes on the truck and not on the trailer, how does a trailer load cause any different flashing since the load from the truck light is causing the flasher to work or is there a second section in the flasher for trailer only?
Is there any way to talk to you on the phone instead of this method?
if there is only one circuit for both the truck and trailer lights, i don't see how the truck can be flashing and the voltage at the fuse for the trailer not flashing since you say it is all the same circuit.
is there any way to show the wiring diagram for this circuit? i still don't understand how the load can cause any flashing since the truck is already flashing and it is the same circuit from what you say.
the drawing you sent shows the output wiring. i don't see where it comes from to get into the cjb from the flasher wiring. on pins 13 and 15. if i had that i may be able to understand how it can only be a constant voltage and not flashing at the input to fuse 42, since the truck is still flashing.
since it looks like it comes directly from the flasher, it should not require a load at the trailer. is it possible it could be the multifunction switch and is so is that the switch on the steering column?