Troubleshooting a P3 Brake Controller Install on a 1998 Chevy K2500 that Wont Go Into Sleep Mode

Question:

I bought a Tekonsha P3 controller from you a while back and have since put it in my 1998 Chevy K2500 to pull my horse trailer. I ran the white wire to ground, black to power with a 20amp breaker installed in line,red to the brake switch which is green on my truck.I was not getting any power to my trailer hook up for the ele. brakeblue wire using a simple light probe tester so I ran a new wire from the controller to the hook up. I dont know if this worked yet as there isnt anyone here right now to step on the brakes while I test it, but I assume that since its a new line 12 gauge it should be working. However, now the controller will not go into silent, or sleep, mode. The light stays on way past the 15 minute time for it. When I ran thru the Trouble shooting tests on the controller everything checks out except for the Stoplight test. Instead of reading 0.00 it keeps going from 0.00 to 5.02, not in any order just randomly. I used my tester on the wire I hooked the red wire to, the green one, the tester only lights up when I depress te brake pedal. Do you have any idea why this is happening? If I cant correct the problem Ill have to unplug the unit to keep my battery from discharging.

asked by: Thomas B

Expert Reply:

I think you might need to find a different stoplight wire. It sounds like its seeing random voltage spikes on that green wire which is preventing your controller from going into sleep mode.

You might want to find a multimeter like our part # PT89ZR to test the circuits on your brake light switch to ensure you find a circuit that sees the full 12 volts when the brakes are applied and zero when the brake pedal is released.

I also attached an FAQ article on troubleshooting brake controller installs for you to check out.

expert reply by: Jameson C