Reverse Electric Lockout Solenoid Not Working using 7 to 4-Way Adapter on 2006 Porsche Cayenne S

Question:

I have a 2006 Porsche Cayenne S with factory tow package. I have a 7 pin to flat 5 adaptor but not this particular Part # C35FR. My problem is I cant get the system to trigger the solenoid on my trailers surge brakes to lock out the anti-reverse function. My trailer and boat mechanic says the solenoid appears to be operating normally when triggered by another power source. Could it be my adaptor and perhaps this adaptor #C35FR could solve this problem?

asked by: Carl M

Expert Reply:

It is possible that the solenoid on the trailer is not drawing enough power for the factory trailer connector on your 2006 Porsche Cayenne S. But first, you will want to test the reverse circuit on the vehicle connector to make sure it is working.

You will need to chock the wheels of the vehicle, apply the emergency brake, and have someone sit in the vehicle with their foot on the brake while they start the vehicle and place it in reverse. Then you will use a circuit tester such as # PTW2992 to test the center pin on the 7-Way. If it does not have power then it is likely not hooked up or its fuse is blown.

If it does work then plug in your adapter and test the 5th pin which is the reverse output. If it does not have power then there is something wrong inside the adapter and it will need to be replaced.

If it does all work then you could either use adapter # C35FR, or install a load resistor # DI34ZR, in line with the wiring that goes to the solenoid. This will provide more draw and it should then work fine with the system on the Cayenne.

expert reply by: Michael H