Who knows about turn signal wiring?

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mopar56

mopar56

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Ok, this is on my 56 Dodge truck, FYI, there is no stock wiring I have completely re-wired it from scratch. EVERYTHING works, gauges, lights etc. Here is my issue, the round tail lights for the utiline box which have LED 1157 equivalent bulbs work when you step on the brakes and when you operate the signals, BUT when you step on the brake when either signal is on then the brake over rides the signal and only the brake lights stay on. Note: my brake light function dosnt go through the steering column as it would on a a body or most cars. The signals do. The steering column is a Chrysler telescoping and tilting column probably from a mid seventies imperial or like car, can't say for sure. The brake switch is a universal Amazon adjustable brake switch which adjusted nicely to fit the pedal. The left signal and right signal are connected in line with the brake light and I used two diodes near the tail lights to keep the signal from back feeding to the brakes. So.....short of adding separate amber lights to the rear circuit which I have contemplated is there any way of making them operate properly?
 
In a standard setup the blinker mechanism interrupts the power to the tail light in question.

So to make one side flash and the other side stay on you have to selectively switch which side the blinker mech is connected to.

The turn signal switch does this

Your diodes prevent back feed but the continuously on brake power overrides the blinking power from the flasher mech.

In a post I drew up how A turn signal switch can accomplish the switching.

I'll look and see if I can find it.
 
Brake light wiring must go through the T/S switch as the brake light circuit is cancelled in a left/right turn.
 
Thankyou for the replies, Dana67dart and Murry, I agree the reason that there not functioning properly is because I didn't send the brakes through the signal circuit I just don't know how to do it? So Dana67dart if you find that diagram I'll be grateful. 273 I watched the video, it's interesting but that is basically what I have and it performs very well except he didn't introduce a brake light circuit in to his display and if he did I think it would have stopped flashing like mine.
 
I'm assuming that your '55 didn't come with the optional T/S. There is an aftermarket ad-on switch and wiring (vintage stuff) that might make your job easier.
 
While Dana looks for his diagram, see if this will help you trace down the connections you need to change.

Send the brake light output to the turn signal switch, not directly to the rear lights. It looks like the brake light output should connect to a white wire that leads up the column to the turn signal switch.

Also, the flasher output should connect to a red wire that leads up the column to the turn signal switch.

I don't think your diodes will keep anything from working, but after changing the wires around if you still have problems you can always jumper them temporarily.

TurnSignalSwitch.jpg


18W is the switched brake light power coming in.

18BR and 18 DGN (Dark GreeN) are the outputs to the rear.

18R is the turn signal flasher power coming in

I8P (Pink) is full time hazard flasher power coming in

18T (Tan) and 19LGN (Light Green) are the two front lamps. NOTE there are two wires branching off because one goes out through the bulkhead to the TS lamps, and the other feeds the cluster indicators

H3 20BK (BlacK) is the horn button
 
Murry, it did have that switch, threw it away years ago, not the look I was going for, this is a hot rod, hence the tilt column so I am using the internal wiring in the column, ( the best I can ) . Mopardude62, thanks for the diagram and idea , honestly after doing some reading I think I have to run the stop light wire through the signal circuit I just wasn't sure how. I'm at work now so will see if I can make that work later.
 
If you're using a column from a mid-seventies Imperial, I would think the turn signal switch would have the same colored wires as in the diagram I posted.

You will have to find the wire in the column (probably white) that feeds the brake light power to the turn signal switch. From your description of the turn signals working, it sounds like you already have turn signal flasher power routed to the turn signal switch.

Remember you will have to completely disconnect the brake light switch power to the brake lights as you have them wired now. If you can find that (white) wire in the column, route brake light power to it, then just let the turn signal switch do its magic and you should have it working.

It's easier to picture in my mind than it is to explain it on paper! Keep us updated!
 
I used switchback LEDs in my reverse lights. White when reverse, amber for signal. The only thing I give up is turn and reverse at the same time, turn would override reverse.
You can get white/red switchbacks of you would prefer to stay with red, but since the reverse is within the same housing/cluster as my turn/brake/tail, and I wasn’t cancelling brake, I wanted some differentiation. Besides, amber is a safer worldwide standard.
I did have to add a wire to make them two different circuits
Oh, and I did need to change the reverse socket to a 2-pin 1157 style from the 1 pin reverse only.

As a side note, I also used switchback lights in my front turn housing. I can turn on the front park lights as DRL without using park and running all the markers, tail, & dash lights. When I apply turn, the switchback turns off the white & flashes amber, when it detects no flash signal for more than 1 second, it will go back to white (again-only IF I have white turned on)
 
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Ok, I've taken a look at the wires, here was what I have...purple, green,blue,black with yellow tracer, and black with blue tracer, these are the wires that I used, I believe I used the purple as power up the column and the other four went out to the four corner signals. There is also a black with white tracer, a solid black a yellow and brown that I did not use . Lastly there is a ribbon of four wires together which are yellow, white, black, and blue, these wires are only about 18 gauge while all the others are 16. I did not use any of the wires in the ribbon, if you are correct and the white 18ga is the brake and that is what a should put my 12v brake wire in, will it effect the 12v purple I currently have going in??. The reason I did not use the white or any other of those three in the ribbon is that it was cut off close to the column by the PO of the column ( can't say why?), but possibly because this coulmn has a factory cruise control lever on the signal arm which i am not using not sure how I would access them now? Maybe pull the steering wheel down to the actuator and see if i could pull those wires up the column, extend then and drop back down? But honestly I believe they are for the cruise control which I will never use. So before I start messing with this harness and with this new info, any thoughts??, BTW, thanks to all for the help.
 
One thing you can do is make a pin out chart.

Basically you choose one wire and check for continuity to all other wires in all possible switch positions.

Eventually you have a chart that will tell you what each word does.
 
Also, I should add I am NOT using the ignition in the column they ignition key is in the dash so that circuit is there, this and the cruise control are why many of the wires mentioned above are not used.
 
Dana67Dart said:
One thing you can do is make a pin out chart.

Basically you choose one wire and check for continuity to all other wires in all possible switch positions.

Eventually you have a chart that will tell you what each word does.
Click to expand...
That is actually how I figured out what wires to use for the signal outputs, I do not remember if I figured out the four unused 16 ga wires, that was all done about two and a half years ago, I'm not sure if I kept that chart I may have to create another?
 
I wonder what would happen if I took the 12v output from the brake light switch ( which currently goes direct to the rear lights) then spliced that into the two supply wires to the rear lights leaving the column to the rear signals? In theory that would interrupt the supply through the flasher? I think?
 
mopar56 said:
I wonder what would happen if I took the 12v output from the brake light switch ( which currently goes direct to the rear lights) then spliced that into the two supply wires to the rear lights leaving the column to the rear signals? In theory that would interrupt the supply through the flasher? I think?
Click to expand...

If the white wire is "bundled" with other wires, it probably isn't the brake light input wire to the turn signal switch. I don't believe you can take the 12V brake light output and splice it into wires feeding the rear tail lamps. You'd be bypassing the turn signal switch and feeding the tail lights with the brake output..... which you already have working. The turn signal switch makes the determination which hot wire (brake light or flasher) feeds the tail lamps.

Dana suggested you make a continuity chart, which is a good idea. You have to know for sure what you're working with. If Dana's suggestion doesn't work, I'd be tempted to pull the steering wheel and look at the turn signal switch, draw a diagram and figure out which color wire does what.
 
Thanks guys, this morning just for s and g I ran 12v thru the brown wire and yellow wires I mentioned I didn't use coming out of the steering column just to see if they would power up the brake lights, a hail Mary, but nothing...I'm going to study the charts you just posted dana67dart thankyou, honestly every thing works almost as it should with the exception of the signal not flashing with brakes on, I'll not be driving this thing all that much so I may just live with it? BUT I thankyou for your help and I'll post back if I can get this sorted out.
 
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Dana67dart, after reading your diagram and post, it was mentioned that a trailer convertor box might work, it seems simple enough, brake wire input, left signal input, and right signal inputs into the convertor then left signal/brake out and right signal/ brake out, I've installed these for trailers before, same principle and easy, would it work??
 
67Dart273 said:
I BELIEVE you could get around that with a trailer towing "light converter" if you don't want to either change the column or add more lamps
Click to expand...
FIXED!!!! So reading through the thread supplied by @Dana67Dart.... @67Dart273 suggested this idea above. FYI back when I originally wired this up I did map the wires to see what was what and that is how I determined how to wire the lights to the column to get the signals to flash but I could not determine how or which wire was responsible for the brake signal wire through the column hence i wired the brake light separately and all worked well except the issue I had where the brake signal over rode the signal when brakes were applied. Anyway I purchased a converter ( some make think this is cheating) but for 37 bucks my problem is solved. I installed the converter box, removed the existing diodes I had and it works mint! So thanks to all that posted to help and hopefully this might help someone else facing a similar issue. I'll post pics of the unit I used.

20240218_140615.jpg


20240218_144454.jpg
 
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Your column and turn signal switch might be new enough that it is designed to have separate turn signal bulbs from brake bulbs.

If that's the case there is no way to make it work with a single bulb setup.

So no cheating doing what you did.

If it works your golden
 
I think your correct, as there is no white wire entering the column except for a tiny one as mentioned earlier I a ribbon for the cruise control. I have no idea what this column came from, possibly something that had separate signal lights as suggested. Any all is good!
 
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