No Trailer Connection on Tekonsha P3 Brake Controller 90195 on a 2000 Toyota Tundra
Question:
I installed the Tekonsha P3 controller with the ETBC7 kit on my 2000 Tundra to pull a 2005 Fleetwood RV camper. After I installed everything as explained in any and all instructions I hooked up the RV to test the lights and brakes. All lights work brakes, running, turn signals, etc. I do NOT hook up the purple wire to the reverse lights at this time, because the trailer has no reverse lights. The issue Im having is that although the Tekonsha P3 is on and everything seems to be working the screen indicates no Trailer connection, so hence the brakes on the trailer do not work. Where should I start? Is it the Tekonsha P3 unit? Should I check the Blue wire from the connector? Which wire allows the unit to recognize a trailer connection? Could the RV connector be wired differently? Thanks,
asked by: Ed
Expert Reply:
I would start by inspecting the connector on your trailer and the vehicle to make sure there is not corrosion in the connector which could be causing a bad or weak connection. If there is corrosion in the trailer side connector, you would need to replace it with 7-way Connector, part # A7WCB. For the replacement vehicle side connector, you would need Adapter 4 Pole to 7 Pole, part # 30717. For future use, I would recommend using Dielectric Grease for Electrical Connectors, part # 11755, on electrical connections to prevent corrosion.
I would recommend checking the blue wire at the brake controller and on or after the connector using a circuit tester, item # PTW2993. With the trailer disconnected, vehicle in power accessory mode and parking brake engaged, have someone engage the manual brake slide on the bottom of the controller. While the manual brake slide is engaged, test the wiring for power using circuit tester after the brake controller and after the connector.
The next thing I would recommend checking is the wiring on the trailer. Check to make sure the brake wires going to the trailer brakes are not cut or frayed. You will also want to make sure the brake assemblies all have a good clean ground connection.
It is unlikely that the Tekonsha P3 Brake Controller, part # 90195, is the problem as it lights up and is showing a diagnostic error. The P3 has diagnostic displays and the No Trailer Connection display that you see is one of the many diagnostic features of the Tekonsha P3. The Blue wire allows the P3 to recognize a trailer connection.
There is a possibility that the trailer connector is wired wrong, but unlikely since your lights are functioning properly. I have linked a picture showing the correct wiring functions on the trailer connector (see picture).
I have linked an FAQ on wiring that you may find as a good reference and a picture of the trailer side connector.

Products Referenced in This Question
Dielectric Grease for Electrical Connectors, 2 oz.
- Accessories and Parts
- Trailer Wiring
- Wiring
- Dielectric Grease
- LubriMatic
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Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional
- Trailer Brake Controller
- Proportional Controller
- Electric
- Electric over Hydraulic
- Splice-In
- Under-Dash Box
- Under-Dash
- Up to 4 Axles
- LCD Display
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7-Way Round RV Style Trailer Connector - Trailer Side
- Trailer Wiring
- Trailer Connectors
- Trailer End Connector
- Plug Only
- 7 Round - Blade
- Optronics
more information >
Product Page this Question was Asked From
Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Accessories and Parts
- Trailer Brake Controller
- Installation Kits
- etrailer
more information >
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Art M.
6/2/2020
I installed the TEKONSHA P3 with the plug and play adapter cable 3036-P. RV will not start with it plugged in. The controller has very light flashing but nothing visible on the screen. Installation was easy, I'm assuming if the adapter cable I am using is the right one if it plugged right into the provided cable easily. Also hearing a "dinging" sound while running the motor and then plugging in the controller.