Vehicle w/ separate stop & turn, trailer w/ stop-turn co

[misterW]

I'm sure this must have been covered before, but I wasn't finding it. Maybe it could even be a sticky, as I'm sure many people encounter this.

So...my truck has separate lights for turn signals and for brakes. My trailer has LED light combos that use the same bulb for turn signals and for brakes.

Question #1: How do I combine the truck's wires for turn signals and brakes (to send back to the trailer) without messing up the truck's lights and causing the brake and turn signal to operate in unison?

Question #2: Assuming I use some type of diode set-up to make sure that the truck's lights aren't affected, what happens if I am braking and turn signaling at the same time? For example, suppose I am stopped on a hill, waiting to turn left. My trailer's brake light will be on, so how will people behind the trailer know that I am turning left?

Is there a way to wire this up, without causing any problems? I suppose I could add separate turn signals to the trailer if I need to, but I'd rather not if I can just wire it up in such a way that everything works.

Thanks in advance!

[sHoootR]

Hey all you need is a Taillight Converter ,most auto part or trailer supply store will have them......I needed one on my vehicle.....Hope that helps

[BPFox]

Tail light converters are pretty much available at any auto parts supply store. 5 wires in 4 wires out. Look for a good price and stock up on them because they do go bad. I switch trailers often and have shorted out more converters than I care to remember. Since my lights are visible on the tow vehicle I just quit buying them. My trailers pretty much only have tail lights and brake lights now. I pull them with a one ton GMC van with the lights placed at the top of the van so the turn signals are always visable. Most likely not an option for you.

[Dale M.]

Other option may be to upscale trailer and put extra lamp holder/fixture and wire identical to truck...

Also some after market wiring harness (adapters - not converter) already accommodate this, you just plug them into truck harness and trailer connector is already converted from three filament per side to two filament per side...

Check trailer sites on i-net that have section for tow vehicle wiring (aftermarket) harnesses....

http://www.hopkinstowingsolutions.com/

Just ordered one for my Jeep and it all of 10 minuets to plug in and test....

Curious as to what vehicle you have that does not have this option....

Dale

[DIY-Stu]

If you are big into DIY and do not wish to buy a converter... Well worth their money... you can make your own using two small relays and four rectifier diodes.
Using the numbered connections as a reference:

If your relay is pulled from a vehicle then you will need to open it's case and remove the internal diode.

Turn to 85 (coil)
Stop to 86 (coil)
connection 30 is your output to the trailer turn/stop
Now for the Diodes
One diode from connection 85 to connection 87 (input) STRIPE towards 87
One diode from connection 86 to connection 87 (input) STRIPE towards 87

REMEMBER: one dual filiment bulb will draw 1AMP for the Stop/Turn Filliment so be sure to make your Diodes match or exceed the power draw of your stop turn lighting for that side.

Description of operation:
Turn ON Stop OFF the 12V+ from the turn signal will feed into the coil through the coil and into the stop lighting of the vehicle where it will get it's ground this is why the coil of the relay needs to require low power to energize. This will energize the relay AND send power through it's diode to feed power through the energized relay to power the circuit to the trailer. The other diode to the stop circuit will prevent the power from continuing.

Same method when stop is on and turn is off.

When both Stop and Turn are ON
both sides of the coil will be 12V+ so it will not be energized. This will cause the Trailer to have the opposite flash pattern than the tow vehicle.

Once again this is if you'd rather do it yourself than buy a converter.