Trailer Brakes
As per another thread, I have yet to change out the 7 pin cable. Prior to doing so, I decided to confirm whether the old cable is still usable. I hooked up the 7 pin to the truck (which recogniz...
Forum Discussion
prichardson wrote:
You need to confirm that you are getting brake voltage at the truck side of the 7 pin connector. If not the problem is in the truck not the trailer.
Old controllers of ages gone by could be tested that way.
NEW controllers, nope...
New controllers are "smart" controllers, they will not turn on the brake controller output unless is has a significant magnet load attached.
Newer brake controllers send a very short pulse of 12V every few seconds, that pulse is too short for most meters to read. Controller is checking to see if the pulse returns (echo or ring back). If controller does not see a echo or ring back or not enough echo or ring back it will not enable any output.
Typically need 1 or 2 brake magnets to trip the output on, incandescent bulbs or resistors may or may not work at all to fool the controller (I have tried that to build a test rig and incandescent bulbs or resistors would not fool any of my trucks with IBC).
