The Stovebolt Site Forums The Shop Area The Electrical Bay Combining the rear brake, tail, and turn lamps

Hey guy's and gal's, I finaly got around to wiring up the electrics on Betty Boop. An earlier topic I posted was about my idea on combining the stop and turn lamps so you don't have to add more lamps.
IT WORKED!!!!! Betty only had 1 brake/park lamp from the factory so I added a rt. side brake lamp that matched the left.
I changed the electrics to 12 volt. And then I went to my local parts house (Advance) and bought an adaptor for adding trailer lights to what is called a five wire system.
A five wire lamp system is used on some late model vehicles that have seperate turn and brake bulbs. This adaptor changes the 5 wire system to a 4 wire system for towing a trailer. It has electronics inside that split the signals. When you go to buy one don't be confused by a differant device called a 4-5 wire adaptor (it ain't the same thing).
Now here is the inside skinny.
The adaptor will only work if hooked to a system that already has bulbs hooked up. That is to say that the electronics inside the device will only work when it sees a load or resistance on the input side.
I got lucky in that the front turn signals are on the same circuit as the rear turn signals so it sees the resistance from the front turn bulbs. If you have a system that the front bulbs are not on the same circuit then you will have to add a 4 ohm resistor (or a bulb) to each of the turn signal wires before it go's into the adaptor.
If you want I can make you a wiring diag. that will help with the hook up.

a wiring diagram and pictures please!

That is a great idea, Toyvo.

Tonkadawg, there is really no diagram needed. The adapter has inputs for the separate turn and brake light wires and output for the combined lights. It's as simple as splicing wires.

Up date-------- I have been told that there is a resistance device used on motorcycles for this purpose. It seems that the bulbs and short wiring harness on a motorcycle dont produce enough resistance to make the flasher flash. So you dont have to wire in bulbs to make it work, just go to a motorcycle shop and get the resistor box.
Once again try hooking it up with all the lights on the front working to see it will go ahead and work with out adding resistance.

I can see where there might not be enough resistance to work a flasher since there would be no brakelight bulbs before the converter as there would be if the box was used for it's marketed purpose. You might also try an electronic flasher made for LEDs if you don't have enough resistance.