Voltage drop measured at Brakes
I am having poor braking on my fifth wheeler. I have installed all new drums and brake mechanisms and I have new batteries in the tow vehicle. My Tekonsha P2 sends out 11.8 volts when manually activa...
Forum Discussion
C Schomer wrote:
Just before I Gave up on elec drums on my last 5er, I ran another 14/2 down the right side so each side had its own 14/2. There was a lot of drop from left to right from the tiny wire inside the axle? I had 11.5 volts max at the trailer cord J box and 11.0 at each magnet after the change. All that work hardly made any improvement. Craig
Well THERES your problem.
simply adding another 14 gauge wire is not enough difference in line loss to be noticeable.
I ran TWO PAIRS of 10 gauge wire.. That makes a huge difference in line loss.
YES, 14 ga is sufficient to handle the 12A draw of the brake magnets.. BUT it IS UNDERSIZED as far as how much resistance the wire presents over all.
Had you gone to 10 ga wire, I would bet you would have brakes that could slam your face into the windshield!
Resistance KILLS the amount of current available, moving up a few wire ga sizes from the old 14 ga factory standards will make a rather drastic improvement in the trailer brakes.
