Turn signal wiring help needed.

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Cope

Cope

Fusing with fire
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Im working on a 1959 chevy and i can not for the life of me figure out these turn signals...

I tried 4 different flashers and still no love.

Each turn signal has its own wire.
They share a common ground.

When i turn on one signal both come on and flash.

The common ground wire seems to be hot?
I dont get it?

I have the entire loom unwrapped. There is no short that i see.

Its like the turn signals are E flashers?

E flashers do work when i turn them on.
 
If the bulbs are grounded at the socket than there should be a common hot wire to feed the blinker mechanism, two connector very common. From the blinker the common wire would go the the common of the turn signal switch. Where it either goes to the left or the right depending on the position of the switch. If there is a flasher cir, in the stock system there are many options and I have no idea which your application would use.

Hope this helps
 
Also you can and should get a wiring diagram. There is a company that makes laminated and colored diagrams. Someone on here mentioned it lately
 
Just remember 'what all' goes into and out of the TS switch and make yourself a truth table

Flasher power into the switch, and tail lamps do not go through the switch

There should be no hazard setup that year unless it was added as a stand alone accessory

Switched brake light power into the switch.

No ground involved with the switch

Output are the stop/ tail, so left turn/ stop and right turn/ stop

Front left turn
Front right turn

If you don't know the colors you can identify the rear by checking continuity. With the switch in neutral, the only wires which have continuity are the brake lights in and the two rear lamps out

Then go from there. With the switch in left, the front and rear left will be connected to the flasher wire.

And you can then eliminate them from there

Along with ground problems, don't discount an internally shorted bulb OR AN INCORRECT bulb, or a socket with the contacts 'disoriented' so that it contacts the bulb wrongly

Ungrounded sockets can drive you nuts. To find, apply power (flasher, whatever) and stab a meter probe into the socket metal, and the other probe to a good ground. If you have to, "rig" a long piece of wire and a good battery clip to battery NEG, etc.
 
I have a new power probe. So i can power up circuits and use the ground on the probe to ground right to the battery.

The only way i can get the turn signals to come on (light up) is ground to one wire and power to another. (2 wire come out of the bulb socket.)

Im thinking the socket should be grounded and both wires are hot. one wire for turn and one for parking lights?

The truck has a newer steering column out of an 80s truck.

I will try grounding the turn signal housing tomorrow.
 
Its actually a GMC, fleetside.

If that helps any?

All the parts say chevy tho.

Lets look at this different.

How do i power up a flasher?

I have 4 different ones.
Lets start with a 2 wire.

If i apply 12v to one terminal nothing.
If i put 12v to o e side and ground the other pin it will turn on for a second before it trips the breaker in the power probe.

3 wire flasher dose the same?

One more tid bit of info.

The 12v that goes hot when i push the turn signal lever down is 12.2V as soon as i hook it to a flasher the voltage drops to 6.6V??

Any idea why?

Like i said i have 4 new flashers of different brands. 2 two wire units and 2 three wire units. All act the same.
 
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Here's a link to a 58/59 GMC pickup. Hopefully this will assist you in tracing the wires, so long the diagram is correct or your harness hasn't been monkeyed with. Good luck.

http://chevy.oldcarmanualproject.com/gmc/5559mm/5559mm302.html
 
Thank you. One issue is that at so.e point the under dash harnes was hacked to mate with the new column so the replacement harnes i bought was not even close to right.
Also the original wire in the truck was so melted i couldn't see any wire color or where the went.

Basically this truck was on fire under the dash and the owner never knew.

Im sure he will state left right up and down it all worked before i touched it tho..
 
How do i correctly power up and test a flasher out of the vehicle?

Thank you guys very much.
I know its not even a MPOAR but i hold the people here in high regard and i know people who can sort out an old MOPAR can certainly help wire a chevy... (edit-GMC..)

:)
 
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Cope said:
How do i correctly power up and test a flasher out of the vehicle
Click to expand...
A typical flasher takes 12v in and the output has to go to a load to function properly. Tie two 12v light bulbs to the output and ground.

upload_2020-2-29_21-2-49.png
 
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Thank you.

Id bet thats why the flasher keeps blowing the circuit breaker in the power probe. (Not enough load.)

I have some old bulbs and sockets. I will wire them up and test the flashers.
 
Cope said:
Id bet thats why the flasher keeps blowing the circuit breaker in the power probe. (Not enough load.)
Click to expand...
I think it is the other way around. you are testing the flasher by applying a direct short with your test probe
 
Yes it is a direct short. I was thinking that adding the two bulbs will lessen the amps/ volts? That the probe sees and not trip the breaker in the probe?

Im verry much hoping that when i groumd the box on the turn signal that it comes on.

Altho even then its remove entire grill to get to the bucket...
 
67Dart273 said:
DAMN Lol THAT thing is hard on the eyes!!!
Click to expand...
I know, it gets even worse as it gets expanded. I guess we get a bit spoiled with how far technology has taken us. Sometimes tho, we gotta do with the best of what they had then.

My jewelers goggles worked best, but then I felt like I was out at sea when I took them off.
 
You don't need a flasher to figure this out, you can just bypass it, or better yet, what I like to do--when I'm "skeered" there might be a short----is to use a heavy wattage bulb in series. That way if there is a short, instead of blowing fuses or burning up wires and switches---the series bulb just lights up

In this case what would work good is to wire up an old headlight, and hook it to the flasher socket. If the TS switch "let's say" is correctly wired for left, you would turn it to left, and both the front and rear lamps would light--as well as your series protection lamp. You could also use a socket and stop/ turn lamp instead of the headlight

I used to do this a LOT with shorts and drains. You can wire your protection lamp in series with the battery ground and the worst that will happen with a short, is that the series-protection lamp will light up
 
Hiw woud i wire that up?
Hot in to one side of the light, hot out to the other headlight pin and ground out the thrid pin on the light, then use the headlight ground and my ground?
 
I'm going to say it again GET A WIRING DIAGRAM.

You keep talking about grounding all kinds of wires.

Tail lights have two wires and the socket is the ground. One wire is the brake / turn signal 12v feed, the other wire is the running light 12v feed.
 
67Dart273 said:
You don't need a flasher to figure this out, you can just bypass it, or better yet, what I like to do--when I'm "skeered" there might be a short----is to use a heavy wattage bulb in series. That way if there is a short, instead of blowing fuses or burning up wires and switches---the series bulb just lights up

In this case what would work good is to wire up an old headlight, and hook it to the flasher socket. If the TS switch "let's say" is correctly wired for left, you would turn it to left, and both the front and rear lamps would light--as well as your series protection lamp. You could also use a socket and stop/ turn lamp instead of the headlight

I used to do this a LOT with shorts and drains. You can wire your protection lamp in series with the battery ground and the worst that will happen with a short, is that the series-protection lamp will light up
Click to expand...

This is exactly what I used to do in my youth when I didn’t have meters and & money to buy parts. I had a couple of different sized light bulbs. Like a dash light and a tail light that I used to troubleshoot depending on how much current I wanted to pass. I had alligator clips on wires a couple of feet long on each one so I could clip them on stuff. You can buy bulb sockets and alligator clips at a parts store or amazon.

Power probes are great, but it takes a little time to learn how to use them if you are not an electronic guy.
 
IDK, Just a thought. Dont know what year they stopped this but could this GMC have a Positive Ground System?
 
Cope said:
Hiw woud i wire that up?
Hot in to one side of the light, hot out to the other headlight pin and ground out the thrid pin on the light, then use the headlight ground and my ground?
Click to expand...

1....The easiest way is to disconnect the battery ground and connect the lamp from a ground (frame or engine block or just hook to the end of the neg cable) and the other end to the batt neg post

2...Or in the case of your signals problem, just rig it to hook to the flasher terminals. I just use a couple of male flag terminals on scrap pigtail wires.

You want your protection lamp IN SERIES so that it limits current.
 
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