Troubleshooting P3 Brake Controller Install that Functions Properly Intermittently

Question:

Just installed a P3 on a 3500 sprinter, I have a couple issues in troubleshooting mode I have 14.5 battery volts, 12.3 stop volts, but no brake volts for about 3 seconds. When I tilt the controller it appears to function intermittently but it functions better. I read something about an aux. brake switch ? My stop volts have been consistent but less then the battery volts.

asked by: Craig I

Expert Reply:

Verify that you have the P3 part # 90195 mounted in the orientation it needs to be to function properly (see picture) and that the red wire is attached to a circuit that sees only voltage when the brakes are applied. Most likely the problem is related to either one of those.

expert reply by: Jameson C