turn signals both flash on trailer

When I turn on the left turn signal on my trailer, the right turn signal will also flash and vice versa if I turn on the right signal. Is this a grounding problem? I need a place to start - any ideas?

Thanks

 

Not a grounding problem as both are working. Is this a new installation? If the tow vehicle has separate turn and stop lights , and the trailer has combination stop and turn in the same bulb - as most do, either you need a converter or your present converter has gone bad. These are available at most auto parts stores and any place that sells trailers.
Only other thought, and maybe your first check, is to see that the turn signal wires are not touching each other with a worn insulation spot shorting the two together.

 

Sorry to disagree but it could very well be the grounds.
I have found on more than one trailer that the ground causes this problem.
Check that each light has a ground wire at the bulb and also the trailer frame. Dont rely on the mounting bolts to make the ground connection. They rust there very quickly. Run a seperate wire to the trailer frame. Also it helps to run an extra wire from the trailer to the truck frame. Use a waterproof connector to allow this new wire to be disconnected when you disconnect the trailer plug.
Relying on the hitch ball for proper ground can cause problems as grease does not conduct very well.
The turn signal could have only one good ground at the trailer lights and therefore has to use both bulbs to complete the circuit.

 

The trailer is 23 years old. I am not aware of a converter on the trailer - I will inspect the wires - thanks

 

Each light does have one ground to the light fixture but not directly to the frame. Do you mean run a ground from each bulb to the frame also?

Thanks for the help

 

so, did it just start doing this after working right for 23 years?

Goldstar has a very good point about the separate turn signals and tail lights on a vehicle and combined units on a trailer. Does this describe your vehicle and trailer or not? I causes a lot of frustration if this is applicable and the connections are not made using the proper connections and devices.

not sure what badeyeben is speaking about with the trailer ball as a ground connection. There should be a ground connection in your plug set. I will agree that the ground connections need to be made good if they are corroded though.

a bad ground can cause all sorts of odd lighting problems.

 

Goldstar is correct - I do have separate stop lights and turn light on my pick-up (2003 Silverado). Since the trailer is 23 years old, I don't think I have a converter on the trailer. What type of converter is it and where could I purchase one. Come to think of it, my trailer brakes don't work either- could the lack of the converter be causing my brakes not to work also? (I do have a brake controller installed). My ground s don't seem to be corroded but I may clean them up anyway

Thanks

 

Most auto parts stores that sell trailer hitches and balls will also sell the 3 to 2 converter.
It basically has separate wires that hook to your right turn signal feed, as well as to the left turn signal and to the brake feed in the car or truck. It has output wires for the left and right lights on the trailer. Some also have a feed hookup for the running/license light.

I don't know what triggers your trailer brakes, but the sending mechanism could have been left on a prior vehicle and not transferred to your current vehicle. A place that sells or rents trailers could help you with that.

 

I tried hooking up to another trailer before I purchased a converter and the turn signals worked fine on that trailer
so it must be a grounding problem

 

Let us know what you find. You learn and we learn.