Originally Posted by Acableguy06
Correct...one wrench to keep in mind is if the light is self grounding or wire grounded. This would not be a question on a fiberglass TT.
No need to worry about the ground if you use a relay
to do the work for you.
For example, the Left Side (right side the same)
Take a low (coil) current relay and
1- Connect one side of the coil to the Left Stop light.
2- Connect the other side of the coil to the Running
Lights wire from the TV.
3- Connect a source of +12vdc to the relay Common
contact and connect the "hot" from the Left Side
Marker lights to the Normally Open contact of the relay.
4- Leave the grounds for the marker lights alone.
When the running lights are off, the markers will flash
ON when the Stop Lights flash ON. Relay normally off,
on with stop light.
When the running lights are on, the markers will flash
OFF when the Stop Lights flash ON. Relay normally on,
off with stop light.
Do the same for the right side.
Works on my Flatbed Trailer..........
1- You need access to the "hot" of
left and right side marker lights separately.
2- Used a 12v NON-polarized relay.
3- A low current relay is needed to assure
4- When you slap on the brakes, Markers
on *BOTH* sides will go on, if previously off
(daytime) and off if previously on (night time).
5- Brakes + Turn Signal + Running Lights =
Exercise for the student......