Voltage at the magnet I only get 1.3 volts when controler is set to max I should be getting closer to 12 volts shouldnt I. even at plug on brake wire at plug on trucki only get 1.3 volt it is a 05 F-350 with factory controller I beleve I have issue on truck would you agree
asked by: David
I agree that you most likely have an issue on the truck side. The voltage at the brake magnets when the vehicle is sitting still and the brake pedal is pressed will only read a small amount with the Ford integrated brake controller on your truck. If you are using the manual slide to activate the trailer brakes you should get somewhere between 12 and 13 volts with the controller set to the maximum setting. If this is the case there may be an issue with the brake controller.
The 2005 and 06 Ford factory brake controllers had issues that cause many owners of these trucks to change out to an aftermarket brake controller like the Prodigy P-3, item # 90195. You can test your factory brake controller to see if there is an issue with the controller or else where.
Access the brake controller wiring behind the dash on your truck, see link. Find the brake output wire coming from the connection to the factory brake controller and sever it, leaving enough room to reattach it after testing. Then using the manual lever fully apply the trailer brakes with the controller set to max, and test the blue wire. If you do not get 12 to 13 volts with the vehicle running there is a problem internally on the brake controller.
If you determine that you would like to replace the factory integrated brake controller, I would recommend the P-3, # 90195 along with the vehicle specific wiring adapter, # 3065-P. This will allow you to attach the P-3 directly to the factory wiring. You will then need to take the truck to the dealer to have the fault code removed from the dash, because the factory brake controller is no longer connected.
expert reply by: Bob G
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Products Referenced in This Question
Brake Controller Wiring
Plugs into Brake Controller
Electric over Hydraulic
2 - 8 Brakes
Product Page this Question was Asked From
Electric Drum Brakes
Left Hand Side
12 x 2 Inch
6000 lbs Axle