I need help with a trailer brake problem

[Snowbird]

Wiring diagram that came with my Pollak connector. I found this to be the standard on all the campers I have pulled. Don't know if this is system wide standard or not. Hope this helps.



1-Ground

2-Electric Brakes

3-Tail & All Running lights

4-Battery Charge to Trailer

5-Left Turn Signal

6-Right Turn Signal

7-Backup Lights (Center Terminal)

 

[Loren]

Snowbird is correct on the pin codes for the plug. I still think that your brakes probably need adjusting, but it sounds like it's also possible that your truck plug is not wired to the standard. Here is the standard layout. Except as noted, 12 gauge wire is recommended for all circuits.



Looking at the receptacle on the truck, at the top is the keyway for the plug. There are three terminals to the right side and three to the left. The layout makes no sense but these are the pins:

Upper right: #4 (black wire): Battery charge (This pin should always have 12 volts. Pollak recommends 10 gauge wire for this pin. )



Middle right: #6 (brown wire): Right turn (This pin should have 12 volts intermittently when the right turn signal is flashing. It should have 12 volts continuously when the brakes are applied. )



Lower right: #2 (blue wire): Electric brakes (This pin's voltage will vary with increased output from the brake controller. )



Upper left: #3 (green wire): Tail and running lights (This pin should have 12 volts when the tail lights are on, e. g. parking lights or headlights on. )



Middle left: #5 (red wire): Left turn (Same as for #6, except for left turn signal. )



Lower left: #1 (white wire): Ground (Should never have any voltage. Pollak recommends 10 gauge wire for this pin. )



Center: #7 (yellow wire): Auxiliary pin. (The travel trailer industry uses this pin as power to the backup lights. Dodge wires the factory receptacle that way. It should have 12 volts when the truck is in reverse and the key is on, that is, whenever the truck's backup lights are on. )



I hope this helps with the troubleshooting.



Loren

 

[Turbo Thom]

Good show Loren. You said it, your right, and that settles it.



Good post, B'Gate.



Preston

 

[Loren]

My curiosity was finally piqued enough actually to get out the meter and measure some voltages. Here is what I learned.



Pin 1: Ground: zero (This is good. )



Pin 2: Electric brakes: 0. 5 - 12. 6 (battery voltage) Note: My brake controller is a Tekonsha sentinel. It can warn me if my brakes are not functioning correctly. (Don't ask ME how it knows. ) I suspect that's what the 0. 5 volts is for when no brakes are applied. I achieved the 12. 6 volt reading by sliding the manual brake slider to the limit. When I stepped on the brake pedal, the reading actually went down a bit to 0. 4 volts. The Tekonsha sentinel is also an inertial controller, with a pendulum. It would not send much voltage to the brakes until it sensed some deceleration.



Pin 3: Tail & Running lights: 0. 1 (I can't explain why there is some voltage here with the lights off. I didn't remember to read it with the lights on. )



Pin 4: Battery charge: 12. 6 (battery voltage)



Pin 5: Left turn: 0. 0 - 11. 7 (I don't know why I'm not getting 12. 6 volts here with the light on. )



Pin 6: Right turn: 0. 0 - 11. 7 (This was the same as the left turn. )



Pin 7: Backup lights: 0. 0 - 10. 7 (I don't know why I don't have 12. 6 volts here either. )



I don't know if this data will help you any, but here it is.



Loren

 

[rickhans]

The voltages less than 12 look normal. Without the engine running and lights drawing from the circuit there is bound to be some voltage drop. The battery charge voltage should be coming straight from the battery with no load on it to cause a voltage drop. You must not have had a trailer hooked up when you did the test else you probably would have seen lower voltages, especially on the brakes.