Toad rear lights

[Hooter G]

Cayman PDQ 2008 and Envoy 2008. I have a Roadmaster Falcon tow bar and use an Even Brake. The brake and turn signal lights (both sides) on the toad have quit when the rig is connected. Tail lights work. The rear lights on the MH and on the toad work when they are disconnected. The wiring diagrams on the Roadmaster site don't give enough detail. So ..... how to troubleshoot? What voltage should I read on the pin-outs from the coach on the brown, yellow, and green to white? Are the brake and signal lights to the cable fused separately on the coach? Is there a fuse on the toad that could be blown? Don't see any loose connections on the diodes. Any help on a starting point would be appreciated.

[justlou]

Yes, the plug at the rear of the coach has seperate fuses for the lights. The fuses on my coach (2006 Diplomat) are located in the roadside electrical bay. They are in one of the small fuse blocks.

[Dutch Star Don]

Hooter G...it ssounds like a power issue at the plug. Throw a volt meter on the plug and see if you get power.

If you've blown a fuse like justlou suggested, don't put a new one in until you take that rear trailer plug apart and clean/inspect. You may have a short at the plug if you blew fuses in that front bay.

[ShapeShifter]

Originally Posted by Hooter G

So ..... how to troubleshoot? What voltage should I read on the pin-outs from the coach on the brown, yellow, and green to white?

Those circuits are nothing special, they just provide the voltage (at sufficient current) to drive the toad's bulbs directly.

• White is ground.
• Between white and brown, there should be 12 volts when the tail lights are on, and nothing when off.
• Between white and yellow, there should be pulsing 12 volts when the left turn signal is on, steady 12 volts when the brakes are on and not the turn signal, and nothing when off.
• Between white and green, there should be pulsing 12 volts when the right turn signal is on, steady 12 volts when the brakes are on and not the turn signal, and nothing when off.

You can measure this with a volt meter, but if the problem is a corroded high resistance contact, the volt meter will still read valid voltage, even if there isn't enough current to light the bulb. As a real test, you could take a tail light bulb, and connect it between the white and each of the other wires to test the circuit under load. (A tail light bulb in a socket with some leads and aligator clips makes a good general purpose 12V circuit tester.)

My guess is that you're going to find either a blown fuse, or a corroded contact/splice.