blinker problems

[bigblock4x4]

i had repaired the wiring on a older trailer got every light working properly parking stop tail lights and marker lights. only issue is left blinker does nothing and right blinker acts a four way flashers. i am stumped any ideas? thank you.

 

[cruiserpilot]

I was going to say check your ground, cause that is almost always the problem. But I think you might have mixed up the wires from your right and left signals.
Do you have a simple test light? So you can confirm that the wires right at the plug on the truck do what you want them to do?

 

[bigblock4x4]

i did check the ground. wires maybe mixed i suppose but i think they are right. i just dont understand why i get no left blinker and the right blinker is actring as four way flasher. and the four way flasher also works in sync with the truck as does everything else. only mix up is blinkers. i will do another run though.

 

[Brentbba]

Are you going direct from the truck or thru an OEM or Hoppy type converter? Sounds like wires are criss-crossed to me.

 

[bigblock4x4]

truck works correctly. i have it hooked up. its a 83 owens classic flatbed. has a 4 pin. any idea of which colors are crossed? i thought everything is matched by color but there has been some patches in the back.fro previous owner,

 

[PAToyota]

Obviously, your trailer is low. You need a fill up...

Seriously, though...

Is there a bulge in the wiring anywhere? You need a converter to take the separate turn & brake lights and combine them. Sounds like you may have it just wired up with four wires and only connected to one turn signal.

You need something like this in the wiring: Amazon.com: Hopkins 48915 60" Tail Light Converter: Automotive

 

[Brian in Oregon]

If you have a bad ground, the current will complete the circuit by following the other filament in the bulb, because they share a common ground. This backfeeds into the wiring and finds true ground via the element in other bulbs.

Whenever attaching lights to a trailer I prefer to use star washers under any nuts. Star washers will cut through the paint and into the underlying metal to ensure a ground. Even so, it is possible for whatever the light is bolted to to have lost its ground as well. For example, a light bolted to a fender which may have corrosion to the bed. Or even a bed that may be too corroded to the frame, etc.

And some trailer wiring has imperfect grounds to the tow vehicle. You can use a jumper cable between the tow vehicle frame and the trailer frame to test for this condition.

 

[jimkyser]

I would try hooking the trailer directly to your battery to test each wire. Use jumper cables to connect to battery or use an eternal power supply or even a battery charger.

All colors mentioned below are the standard ones, yours MAY be different. The white wire is ground so connect to the '-' on the battery and leave it there for the next three tests. The brown wire is for the running lights, so connecting the battery '+' to it should light both taillights. The green wire is for the right tun signal light, so connecting the battery '+' to it should light just the right taillight. The yellow wire is the left turn signal, so connecting the battery '+' to it should light just the left taillight.

Try each of these connections individually and see if the lights work properly.

 

[PAToyota]

If you have a bad ground, the current will complete the circuit by following the other filament in the bulb, because they share a common ground. This backfeeds into the wiring and finds true ground via the element in other bulbs.

That wouldn't explain why one side flashes both lights and the other side flashes neither.

I would try hooking the trailer directly to your battery to test each wire. Use jumper cables to connect to battery or use an eternal power supply or even a battery charger.

Sounds like all the lights work but that the "signals" are getting crossed somewhere.

I still say it is that there isn't a converter in the system to go from separate turn and stop to combination lights.

 

[jimkyser]

It sounds to me like the repair work he mentions in the first post connected the left turn signal AND the right turn signal both to the green wire (right turn signal) and the yellow wire (left turn signal) isn't connected to anything. The behavior he describes is exactly what would happen in that case. Isolating the trailer and testing it by itself would flush that out pretty quick.

If all the correct lights work when working only with the trailer he will then know the issue is in the truck side of the wiring. But since he admitted to recent work being done to the trailer I suspect that is where the problem is.