Troubleshooting No Power To Tekonsha Prodigy P3 Brake Controller
Updated 02/17/2026 | Published 06/24/2024
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Question:
No power to the Prodigy P3 brake controller on Ford E350 2003 RV. Used your universal kit to put 7-pin in had existing 4 pin. Ran wires. Black via 40 amp fuse to positive battery. White to blue wire on 3035-p adapter. The weird thing is that someone had plugged in just one green wire into the towing harness under the dash. It looks like maybe previous owners had a brake controller and just cut it out, except for wire to blue in harness. Regardless, when I set up as per your videos, no power to P3. Help please.
asked by: Janine M
Expert Reply:
Hello Janine. You do have the black wire from the Tekonsha P3 # 90195 connected to 12v power, correct? If so, you should be getting power to the controller. It is hard to say exactly what the green wire is for, but for the P3 controller black is for power, white is ground, blue is brake output and red goes to the cold side of the brake switch. Please make sure all of these connections are correct. You can use a Circuit Tester like part # PTW2991 to test each wire to make sure the functions are correct. This will be the best way to narrow down the cause of the issue. It also may be easier to do away with the # 3035-P adapter and simply hardwire the controller.
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Jesse M.
2/17/2026
Hey Janine, what ended up happening with your Prodigy P3 controller on the E350 after checking those wire connections? Knowing whether the circuit tester helped you track down the power issue could really help others troubleshooting similar wiring setups.