Brake Controller Overload

guitarzan wrote:
Prodigy Controller (10 years old) works intermittently then fails and reads OL or SH.
Cleaned 7-way plug and inspected wires not including inside drum. Took the TT for a spin and brakes still work sporadically.

Checked wheel temps when I got home
Front
98. 116
82. 115

I recently repacked the bearings and magnets looked normal did not take a good look at the wires but did shoot some brake cleaner on the magnet spring mechanism and everything seemed fine. Maybe I set the brake too loose on left rear, or else it's shorting somewhere?

I'm wondering if the controller is failing as it was really acting wonky. When it's working, if I hold the brake it reads about 1.6 and after 3 seconds it drops to .06 and then holds at 1.0. That's not right. It should increase by a big percentage and hold. What the heck? Wire shorting, bad connection, or failing brake controller?

Ya'll have any ideas? I'll be obsessed with it until I get it fixed...

Your controller IS designed to REDUCE the output (less than 25% of max if I remember correctly) once the vehicle has stopped. So, that looks to be "normal" operation.

PER MANUAL.. HERE

Under "IMPORTANT FACTS TO REMEMBER"

"3. The Prodigy P2 will “HOLD” your trailer with 25% of power setting while you are at a stand still with brake pedal applied for longer than 5 seconds"

The intermittent OL and SH is telling you that you have an intermittent SHORT in the wiring (most likely the trailer).

The typical place for intermittent shorts is at the axles.. The factory runs the BRAKE WIRING THOUGH THE AXLE TUBE..

The wiring inside the tube is free to swing and move around inside the tube.

This movement CHAFFES the insulation until it wears off enough to intermittently short.

The fix is to cut the wiring to the axle tube and RUN NEW WIRE ON THE OUTSIDE OF THE AXLE TUBE.

As far as someone mentioning checking the resistance, that is a worthless test. The resistance is too low for most DVMs to reliably read it.. Better way to check is by checking the AMPS drawn..

Also your brake controller uses PWM (Pulse Width modulated) to regulate the output.. It sends 12V but chops the time on/off to achieve a variable output.. Makes it hard to read the voltage using a DVM..

On edit.. Adding info from Prodigy manual in red..