The Stovebolt Site Forums The Shop Area The Electrical Bay Brake/turn conversion module

Ok, I have three 1157 sockets (12v, neg.gnd) on the back of the Juggernaut, and I want to have all three function as both tail and brake lights with two of those as turn signals. I need to know if this thing , rated for a maximum of 6 amps per side, is going to work. If not, where can I find the right item? Anyone got a schematic of the unit so I can build one?

edit: I'm running extra bright 1157's and have no intention of buying LED replacement bulbs.

You could use a seven wire directional switch, which allows the same filament in a bulb to act as brake and directional lights..

If you are trying to use one as just a middle brake light, you need to run a wire from the brake light switch to the middle light bright filament.

Signal Stat and Grote are two manufacturers that sell units that clamp to the steering column..

So basicly you are running a Third Brake Light with the third socket? I agree with 53 just wire it to the switch. As for the other 2 lights I would put the 40 bucks toward a Seven wire turn signal.

Good luck and let us know what you end up doing.

Perhaps I didn't provide enough background.

I have a stock signal switch on the column, and it's staying. I have a pair of pods hanging off the back corners w/ 1157 sockets. They are currently tail/turn only. I have one brake/tail light on the door, which I consider inadequate given the improbably short attention span of other drivers.

My question is, will this unit handle the amp load or just go pop? Most of these units are made for low-amp motorcycle circuits and I need to find/build one for my truck.

Most brake/tail circuits run about 8 amps if the front running lights are included. If you run rear lights only, you MIGHT get away with 6 amps...ie. No margin. I would probably try another route.

35w tail light bulb draws less than 3A@12v. BUt the seven wire signal stat switch would be a better choice.

The wiring diagram for the device you're looking at appears to support only making the two rear turnsignal lamps also function as brake lights.

So if you buy that thing you still don't have a solution for making the third light act as a brake light. You'll probably need to do as someone else suggested and run a separate wire from the brake switch to operate the third light.

You could always use relays to make sure you are not exceeding load limit of the black box.

Am I not being clear? I have three dual filament sockets. All three are tail lights on the "dim" circuit. I have a stock turn signal collar on the column. It goes to the two pods in the "bright" circuit. I have one brake light on the door and want to use the linked device to use the pods as brake lights as well as turn signals. That's what the thing does, only it's designed for motorcycles.

I am not going to buy a clamp-on signal switch. I am not going to buy LED bulbs. All I want to know is if that device will melt down in my truck, and if so what alternatives are available? I am open to the idea of building my own or adding fuses/relays to protect the circuit, I just don't know if it's necessary.

From what I can tell about the modual, it lights up the turn and brake at the same time for more light and safty? and also lets the turn signal override the brake? so at any given time it will have three light lite in the brake mode? All three ( left turn, brake, right turn) will come on when braking, or two will come on when braking and one flashing when turning. It sounds to me like it will power three bulbs OK if I understand it correctly. It would be a little extra work, but you could wire this unit to turn on three relays that will each handle 20 amps. Then it would last forever and you would know each bulb was getting full battery power. Joe

Joe, you're correct as to the function of the module. If it senses a load from both the brake and turn wires, it shunts off the brake voltage on that side and lets the turn impulse through to the bulb.

Here's a thought: What if I were to build a logic circuit out of relays? Seems to me I could make this happen with four relays and some creative wiring. On each side, the first relay would open when the brake is applied and divert the turn signal to a second relay, which interrupts the brake light. When the brake is off, the first relay lets the turn signal impulse get to the bulb directly. This would mean only the brake or turn signal can be hot (at the bulb), not both at once. I think I have enough juice to run such an array, that's why I was worried about melting the module. Is this a product of sleepless delerium or could something like this actually work? :confused:

Where's an EE when you need one? :p

You can get the same "Logic Circuit for Third Brake Lights" from JC Whitney for $5. I have it on two cars. One I bought was bad, but the other two work fine.

Search on 'logic circuit' at www.jcwhitney.com its listed with the truck third light.

I use it on my Nova with halogen turn bulbs.

Jim

Jim, can you describe the hookup on that logic circuit, or do you have a schematic for it?

I think this schematic is what your looking for:

http://www.50chevy.freeservers.com/Electrical%20How%20to\'s.html#Early%203

I made my own system using four relays and a flasher unit. The switch is a small toggle mounted just under the dash and the indicator lights are 12v green LED's. It works great, only thing you have to manual cancel which is,t a big deal once you get used to doing it.

I have a schematic showing how it works, only its 2.5 meg and everytime I reduce the size you can't read it. I guess I will have to redo it small to start with if you would like to see it.

Its pretty simple if you understand how a relay works.

The front turn lights are wired through the Normally Open contacts, and when you turn on the switch, it pulls the relay closed and the lights get power from the flasher unit.

The rear turn lights are also on the Normally Open contacts and work just like the front lights.

The brake likes are wired through the rear relays only and are on the Normally closed contacts. They work straight through the relays, as if they are not in place. When the turn switch is activated left or right, it closes the relay shutting off power from the brake switch and turning on power from the flasher unit.

Since left and right are separated, one brake light is always on when turning.

I used 20 amp five prong relays. Joe

Thanks everyone, got the info I needed.