Technical Wiring Integrated Turn Signals

Hi all,

I have a painless wiring kit that a friend gave to me (which may be more trouble than its worth on a full custom, but still helpful). The kit talks about integrated rear turn signals and separate rear turn signals and how you need the correct column and turn signal switch for each. But I am trying to put Integrated turn signals on a column not meant for it using some bosch style relays. Basically instead of having a dedicated yellow light, my brake lights will do double duty.


My only concern with the diagram I made is whether or not the flasher input to the relays will work. I was thinking to jumper terminals 85 and 87a, but then the light will be flashing and the relay will be flashing. Any opinions??

 

Ok, to wire in turn signals that share the rear bulbs with the brake and tail lights, you have to get a little creative... What you have to do is make the brake light wires and the turn signal wires combine in a way that the turn signal wires can override the brake signal. There are complicated ways to wire in multiple relays to do it, the way I read your diagram, it won't work. There are aftermarket units that will do this but there is an easier way...
A quick and cheap way that works just as good is a tail light wiring converter for trailers. They will combine the brake wiring and the turn signal wiring so they will work.
They look like this:

 

Hmm good to know, that should be as easy as it gets too. Im just curious what you see wrong with my diagram now.

 

What I see wrong, is that when you put power through the coil of your Bosh Relay, you will switch from NC to NO, and your drawing doesn't show a 5th terminal...


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You've got the right parts, just not the right hook-up....

Connect your power from the brake light switch to terminal 87A. Power from the turn switch/flasher to 87. Connect the rear lights to terminal 30. Leave the relay coil connections as they are.....

This for the rear lights only; if running front turn lights, connect those to the 87 terminal.

 

Hmm ok, so is this what most people do or just use the trailer converter? Seems like the trailer converter would be much easier.

 

I bought the Rebel Wiring Kit and they walked me through my directional questions... Painless and Ron Francis do the same...
I like the directional module shown above because it's autonomous to the rest of the system for easy diagnosis and repair.

 

Now Im curious, how would the relay behave with a flasher input to the coil as I drew and as you suggested. I was thinking the relay would "flash" and eliminate the need for a fifth connection on my diagram.

 

There is no power to the turn signal and no load for the flasher! The only time there would be power to the turn signal is when the brakes were on.

 

Oops, I misspoke....

Actually, neither of these circuits would work right as drawn/explained. With what you have, it would just 'blink' the brake light momentarily if on (the amount of time for the contacts to change states). What you need to do is separate the turn signal switch contacts from the flashed side of the circuit; use the switch to supply power to the relay coils only (so that when the switch is 'on', power is uninterrupted to the relay coil) then take the wire from the flasher directly to contact 87 (not through the switch). This will work for the rear signals. To add front signals, you'll need two more relays, one for each side wired the same, just with no connection to 87A. So what you'll have is:
1. Turn signal power goes to the switch and the input side of the flasher.
2. Output side of the flasher goes to contact 87 on all relays, not to the switch.
3. 'Left/right' switch outputs go to contact 85 on respective left/right relays.
4. Contact 86 is ground.
5. Brake light power from the brake light switch goes to contact 87A (rear relays only).
6. Lights connect to contact 30.

Your circuit won't work because the relay coil won't present enough load to operate the flasher. You could make it work by adding front lights connected to contact 85 if the lamps present enough load, but this will still shorten relay life because they will flash with the lights. If you want to add a dash indicator light or lights, for left/right lights connect to the front lights. For one indicator connect each side of the light to the left/right front lights (no ground; the lamp will get it's 'ground' though the unused light). If you don't run front lights but still want a indicator light, you'll still need the 'front' relays to prevent feedback to the brake lights.

You don't say what you're using for a turn switch, if it has more than three wires coming out of it you may have more options.

 

This worked for me:

 

I've always enjoyed your 12v posts Steve, in this case isn't it easier to just use the tail light converter?

 

You could use one of Hopkins 48895 trailer converters for your project. Draws power from the turn signal switch or brake switch and sends to lamps. Small little box with wires. They work good. I should know, I work for the company.

 

I wired up my ride the other day using a Hopkins converter. It's extremely simple, works great...

Study this: http://www.how-to-build-hotrods.com/turn-signals.html

Interesting note, when I did mine this way, I didn't have the front turn signals/park lights wired yet, in that scenario my turn signals would stop flashing when I stepped on the brakes. It needs the extra draw from another bulb in the circuit to function properly. And if you're doing LEDs, make sure to get a converter set up to run them.

 

Well, maybe.... LOL. But the OP has the relays, so rather than spend more of his money, this works. Another consideration is the relays are 'fail-safe' (a relay failure means no turn signal, but the brake light will still work), not something that can be said for a convertor.

 

Good info here, whatever direction I decide on, I now have the knowledge to do so, thanks all.

 

I'm going to try to revive this one because now I'm at the point of testing all my wiring. I went with a converter as shown below

Esentially the hazards come on every time i want to turn right or left. So I measured the resistance between the left and right inputs on the converter box and its on ly 250 ohms. Seems like the box is shorted internally? Anyone else have this problem?

 

If this converter is anything like the cheapo units we make, it will need to be wired to the turn signal (yellow left and green right) and brake switch (red wire). The issues that you have is that these types of converters depend on the brake and turn signal bulbs for internal circuitry to work correct. In your case you are using the turn signal switch and brake switch for the converter input signals. Since both switches are open when in the off positions, you have no returns. Easiest fix, get 3 1k 1/4 watt resistors from the Shack or wherever. Connect one lead of each resistor together so that the 3 resistors are wired together. This 3 lead connection will be connected to a good ground. Now wire one of the resistor free lead to the red wire, another resistor free lead to yellow wire, and the last resistor free lead to the green wire. Note: The yellow and green wires that get the resistor connections are on the side of the red wire. This should allow a return path for the converter to work correctly. The yellow and green wires with the resistor connections will go to appropriate turn signal switch connections, and the red wire to the cold side of the brake switch. Good luck.

 

So who has a good converter ?

 

So are you saying that once I actually install the bulbs, the unit will work fine? Because now I'm just using my dash indicators to see what's working. Thank you for the input.

 

If your dash indicators are working correctly, you might just have to put a small dash bulb from the stop light switch (cold side) to ground. That will allow the stop wire (red to have a ground return thru this small bulb). The left and right will return thru the turn indicators. The left and right bulbs have no effect on the converter, as they are only connected to the converter outputs.

 

There is something that everyoone is overlooking. Factory turn signal switches come in two different designs. Cancelling and non-cancelling. Basically, any system using a dual element bulb for tail and turn/brake light,cancels the brake light on the side you are indicating for a turn. When wheel r
Is returnedto center both brake lights return to use. A non-canceling switch uses two dedicated bulbs, one for brake and one for stop the same as european cars do. Find out which switch you have and get a matching wiring diagram and follow it. Almost all late modelcars except for trucks have gone to the non-cancelling switch. That will require and tra circuit and bulb for our older cars. A cancelling switch will usually be a seven wire switch, left front and right front turn, lrft rear and right rea brake/turn, turn signal power, 4way flasher power, and horn. No need to do any add on relays or anything else. Most aftermarket t/s switches are of the cancelling type also and function the same way. They just will not turn off after the turn is complete. That is up to you, or leave it on and make everyone think you are circling the world to the left or right.

 

What if you used a tailight converter that had a a ground wire going in and out of it?
Like the draw-tite 119130?

 

Trailer tow converters take care of the "cancelling". They have separate turn signals and brake signals going in, and turn/brake coming out. The logic in the allows a simple SPDT center off switch to be used in conjuction with the brake switch to combine the signals properly.

 

The converter you are using is referred to a "non powered converter". In our converters, the tail light and ground simply pass thru. The left, right and stop signals are fed to internal circuitry to "combine" the left/brake or right/brake to make the rear lights combinations turn/brake lights.

 

After your responses, I'm pretty confident in my wiring and I think I'll wait until I hook up the bulbs before any further worrying. The fact that the output signals are essentially open circuits makes sense that funny things could be going on with the indicators. Thank you for the responses.

 

If you are wiring the converter to the turn and brake switches, and the output of the converter are for the rear turn/brake lights, the bulbs will do nothing to help the converter. The returns must be on the input side of the converter. In your case, you do have left and right turn indicator bulbs, which do work to establish returns, but the brake switch does not. Either a 1k resistor or a small indicator bulb (not led) will do the trick.

 

I suppose a fella could use one of these with an antique 4 wire turnsignal switch, is that right?

 

A four wire turn signal switch with 4th wire as a ground (for the pilot bulb ground) ?? Usually only 3 wire switches are used for simple turn signal switch. Both will work, but need returns such as dash indicators (Left and right), along with brake switch return (bulb or resistor going to ground).

 

d2-willys: Could you explain what you mean by "Returns"?