In times of past the bulb for the brake light, turn signal and running light was one bulb with 2 filaments in it. It was easy to see the filaments and to also identify the bulb because it has 2 round lead connections on the bottom. One filament is the running light and the brighter one is the Stop/Turn. The other smaller filament is the running light, it is on when you turn on your headlights.
When you applied the brakes
, both the left and right bulb bright filament would light. If you applied the brakes
and the turn signal at the same time, one bulb would remain lit and the other would blink. If you applied the turn signal only, then only that bulb would lite.
If you have your headlights on then the smaller filament is lit and the larger, brighter filament will be the brake/turn light.
NOTE: This is how USA Camping and utility trailers are wired.
Is there an exception? You can bet that someone will tell us that they saw a trailer wired different.
You can check your trailer to see if the tail lights
look like this:
1 dual element bulb behind the Red lens and 1 single element bulb behind a clear lens if it has backup lights and 1 small bulb or a clear lens under the left side red lens that will cast a white light on the license
Foreign Cars: The foreign cars that have a RED stop and running lights and a Yellow turn signal require a special solid state device to be installed on the tow vehicle to properly change and operate the trailer lights to the US specifications.
This device changes the foreign configuration to the US specifications. You can find plug compatible devices and cables at the following places:
e-Hitch.com | Taillight Converters
etrailer.com - Products t connector
My 2007 Chevy Silverado Classic has a separate bulb for the turn signal and a separate bulb with 2 elements in it for the running lights and brake light. In other words, it is wired like the foreign cars. It came with the tow package so somewhere in the vehicle they installed a converter so trailer lights would be at US specifications.
If yours is wired like mine then there is a possibility that you can get a plug in T-Connector that will straighten everything out.
I suggest you contact the above web sites, tell them what your tow vehicle is and they should be able to tell you what you need.
If it is a T Connector then just lay on your back under the rear bumper and install it in less than 10 minutes.
Check aznative post of the wiring diagram