Trailer Turn Signals

Electrical and electronic topics for small boats
Papag
Posts: 12
Joined: Mon Aug 03, 2020 8:00 am

Trailer Turn Signals

Postby Papag » Sun Sep 06, 2020 6:10 pm

I can't figure out the lamps on my boat trailer. Brake lamps work. The turn signals are a problem . Left turn lamp works. When I put on the right turn signal, both left and right lamps flash (like emergency blinkers).

Give me suggestions on how to diagnose. Thanks

jimh
Posts: 8260
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: Trailer Turn Signals

Postby jimh » Sun Sep 06, 2020 9:40 pm

Check the trailer ground connection to the tow vehicle.

Check the actual voltages at the tow vehicle without the trailer connected. The problem could be in the vehicle.

Your description is hard to understand. On most trailers in the USA the brake lamps and the turn signal lamps are the same lamps. Their illumination is determined by the current from the towing vehicle.

Are you in Europe?

Vehicles in Europe use separate lamps for turn signals and brake signals. Those signals are usually modified by a convertor device if the European vehicle is to be used to tow an American trailer with American trailer lamps.

Is your towing vehicle European?


All lamps on a trailer share a common negative circuit. On some trailers the trailer chassis is used for the common negative circuit, while on other trailers each lamp has its own negative circuit conductor run forward to a common junction.

jimh
Posts: 8260
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: Trailer Turn Signals

Postby jimh » Thu Sep 10, 2020 11:12 am

See my article

TRAILER-VEHICLE CONNECTOR WIRING
http://continuouswave.com/whaler/refere ... iring.html

For more details on electrical circuits involved in trailers.