Troubleshooting Prodigy P3 Brake Controller that Will not Function When Mounted in Cab of Truck

Updated 01/09/2017 | Published 01/07/2017

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Question:

When I hook-up any trailer my P3 Tekonsha controller will it doesnt works most of the time. If I use the manual control it works. If I move the P3 Prodigy around and lay it on the floor board it will work. As soon as I mount it into the holding brakes it stops working. All other features work. Lights, turn signals and running lights. Any ideas? Thanks

asked by: John S

Expert Reply:

I'm thinking you have the Prodigy P3 # 90195 mounted so that it isn't level horizontally. It can be mounted at any vertaical angle but must be level horizonally. See the diagram I've attached.

Another idea is there is a short in the wiring harness # 3016. It's possible the wiring is damaged slightly and therefore when it is bent in the fashion that it is when the controller is mounted on itss backet it loses connection. Since it still works using the manual switch then the issue would likely be on the red wire. You can use a multimeter, like # PT89ZR, and test the harness. Put a test lead on each end of harness on the corresponding pins for current. Bend the harness in different places and in different ways while testing. If you lose current with it bent at a certain angle then you found the problem.

expert reply by: Charles S