*Turn Signal Not working*

[Zippi]

I thought I had ask about this before but I can't find it. I have seen my front right hand turn signal work before but it no longer works. All my other lights work as they should. The bulb was good but I changed it anyway. I traced the wires down and the two wires come off the right hand side turn signal into a loom and travel to the left hand side where it splits off and goes to the left hand side turn signal. They both seem to head up to the firewall to the steering column I guess. I did find a black wire on the right hand side coming out of the loom and I thought is was the ground for the turn signal so I ground it hoping that was the issue but I got nothing. Not really sure what that wire is for.

[dmjlambert]

Well I can't say I recommend grounding a wire that you don't know for sure should be a ground wire. You may cause a short and burn up some wiring.

I recommend do this:
Get a test light from the auto parts store or Walmart, like this:

Here's one. https://grocery.walmart.com/ip/EverS...-Tester/876900 I don't know for sure that link will work nationwide.
You don't need to go into the store for this. Just order it online for free pickup or a small delivery fee, you can order it at the same time you order groceries, I suppose almost all Walmarts have order online and go pickup in the parking lot, a clerk will load the groceries right into your trunk (or pickup bed). grocery.walmart.com You don't even need to roll down your window.
Anyway, to continue...

Attach the alligator clip end to a good clean metal ground somewhere under the hood. Touch the pointy tip of the tester to the battery + terminal and check that it lights up. Turn on the left turn signal that is working. Remove the blinking bulb and touch the terminals inside where the bulb plugs in. You may need to turn off the blinker and let the bulb cool down before you try to remove it, then turn the blinker back on. If the tester blinks on one of the terminals, then you may have dirt or corrosion built up on the terminals and you just need to clean them up. Practice on the left side that is working, so you'll know what you're looking for when you get to the right side.

Test your bulbs by swapping them from one side to the other.

If you don't have voltage at the bulb terminals on the right side, then you can work your way to the wiring like so:

Poke the pointy end through the insulation of one of the wires near the turn signal light housing. Verify the test light blinks. If it doesn't, poke a different wire. The wire that carries the turn signal electricity will be found this way.

If you discover electricity is going to that point of the wiring where it enters the turn signal housing, that probably means you have a bad connection at the crimp connection where the wire connects to the turn signal light housing innards.

You can also use the test light to check for a ground. The way you do that is connect the alligator clip on the tester to the battery + terminal. Then whatever you poke with the tester that is a good ground will cause it to light.

Sometimes people have problems with the bulbs being inserted backwards. It depends on the type of bulb the housing takes. I'm not familiar with your model year, but others on the board are. Post back with your findings, and pictures of what you're dealing with, if you can, and what is the bulb type you are inserting. I don't know if on your model year the parking light and turn signal light are in one bulb with dual elements. Let us know what you have. Ask lots of questions. I'm sure somewhere around the forum is a wiring diagram for your year, or if you have the service manual then you may already have the wiring diagram and we can help you interpret it.

[dmjlambert]

Also, check that you're using the right bulb. Some bulbs have 2 contacts on them, and some have 1 contact. Looking inside the socket on the truck you should have the same number of contacts as on your bulb. I don't mean to point out something you may find painfully obvious, sorry, I don't know your knowledge level on this stuff. I saw your signature line, that is good. You can fix some electrical things with duct tape!

[Zippi]

Great advise fellows. I do have a test light and I'll dig into this this coming weekend. I'm headed back to work today. Kinda scary if you ask me. I'd rather stay in the garage isolated.

[Zippi]

Weather was so nice when I got home I decided to trouble shoot the right front turn signal issue. Using my test light I found that both left hand and right hand side turn signals have a good ground with my test light connected to the positive side of the battery and touching inside the light socket to the bottom contact. Now with my test light connected to the negative side of the battery with the ignition and turn signal on my test light flashes on the left side when I touch it inside the light socket on the top contact. The right hand side does not flash. Looks like there is no power to the right hand side. I also tested the black wire I found hanging down and it was not a ground and had no power to it. So....the turn signals have green and black wires so I'm assuming the green is power. Looks like I need to track down where it goes which may be hard since it goes in some loom with other wires.

[dmjlambert]

What do they do when you have the headlight switch half way out in the parking light position? Or does your model year have that?
How are the back turn signals and parking lights acting?

[Zippi]

Originally Posted by dmjlambert

What do they do when you have the headlight switch half way out in the parking light position? Or does your model year have that?
How are the back turn signals and parking lights acting?

With the headlamp switch pulled half way out both front running lights come on as they should. Back lights work as they should. So there is power to the right hand front turn signal lamp just not for the turn signal.

[dmjlambert]

I recommend with the parking lights on, use the tester to poke through the wire insulation near the turn signal/parking light housing and make sure you know which wire is for the turn signal. It would be the wire that does not light the tester. Hopefully it is a distinct color compared to the left turn signal wire and parking light wires. You can probably then trace the wire back towards the firewall and test at the connector where it goes through the firewall, then move to inside the cab and test along the wire path.

There should be a way to use the tester to send voltage into the turn signal switch and see that it arrives back out of the correct terminal when the turn signal switch is in the appropriate position. Somebody on the forum may have information about how to do that. A wiring diagram for your model year truck may help. I recommend post back with pictures when you get to that point. It could be you have a bad turn signal switch. But you never know, you may find a break in the wire or at a terminal on a connector, such as at the firewall.

[Zippi]

Originally Posted by dmjlambert

I recommend with the parking lights on, use the tester to poke through the wire insulation near the turn signal/parking light housing and make sure you know which wire is for the turn signal. It would be the wire that does not light the tester. Hopefully it is a distinct color compared to the left turn signal wire and parking light wires. You can probably then trace the wire back towards the firewall and test at the connector where it goes through the firewall, then move to inside the cab and test along the wire path.

There should be a way to use the tester to send voltage into the turn signal switch and see that it arrives back out of the correct terminal when the turn signal switch is in the appropriate position. Somebody on the forum may have information about how to do that. A wiring diagram for your model year truck may help. I recommend post back with pictures when you get to that point. It could be you have a bad turn signal switch. But you never know, you may find a break in the wire or at a terminal on a connector, such as at the firewall.

Good info. I'll tackle that this weekend. I'm still thinking its that black wire I found dangling down off the radiator. I tested it for ground and hot with nothing turns on and I got nothing.

[RustyPile]

There is no black wire associated with the right turn indicator unless someone has been hacking around up there.

All the following testing is done with the ignition switch on and the turn signal switch in the right turn position. Does the right turn indicator light work in the dash?? The inside indicator lights share power with the front turn indicator lights.. If the inside indicator blinks or at least comes on, then the turn signal switch is good. If the inside turn indicator doesn't work and/or there is no power on that blue wire, the turn signal switch is bad. At the connector where the steering the column harness connects to the main harness, back probe the blue (not light blue) wire.. If you have power there, you have a break in that blue wire between the connector and the bulb.. First place to check for break in continuity is the bulkhead connector behind the fuse box..

[RustyPile]

Without a wiring diagram, you're sure to go down a lot of rabbit holes, especially searching out that black wire....

[dmjlambert]

OK, apparently I don't have enough to do. :-) I've been researching turn signals on old trucks. 1949 didn't have any!

So, whatever is on your truck, it's not required and didn't come on the truck. According to what I read on the Internet, it was an option in some years and dealer installed option in some years. Not really clear what years, but 1953 appears to be the turning point for cars. Not sure about the trucks. You were supposed to stick your arm out the window and give the signal with your hand.

So, my whole reason for saying this is the wiring diagram won't help. Here's the wiring diagram
http://chevy.oldcarmanualproject.com...49ctsm1202.jpg

If you have an aftermarket turn signal switch or after market or later model steering column in the truck, or some other switching system that your truck has, you will need to trace those wires.

We probably need some 47-53 truck owners to chime in here. I try to help where I can, but I have a 69.

[RustyPile]

Originally Posted by dmjlambert

OK, apparently I don't have enough to do. :-) I've been researching turn signals on old trucks. 1949 didn't have any!

So, whatever is on your truck, it's not required and didn't come on the truck. According to what I read on the Internet, it was an option in some years and dealer installed option in some years. Not really clear what years, but 1953 appears to be the turning point for cars. Not sure about the trucks. You were supposed to stick your arm out the window and give the signal with your hand.

So, my whole reason for saying this is the wiring diagram won't help. Here's the wiring diagram
http://chevy.oldcarmanualproject.com...49ctsm1202.jpg

If you have an aftermarket turn signal switch or after market or later model steering column in the truck, or some other switching system that your truck has, you will need to trace those wires.

We probably need some 47-53 truck owners to chime in here. I try to help where I can, but I have a 69.

I need to chime in on this too.. I made an assumption also.. My mistake was in thinking about '67 and later trucks.. I have no idea what year the OP is working on, so maybe the OP can enlighten us on what he is working on -- aftermarket turn signals, owner installed turn signals, dealer installed turn signals, a truck besides the one in his avatar????

[Zippi]

I have a 1949 Chevy 5 window truck. All the lights are aftermarket. All the wires appear to be new as this truck was built in 2015. My steering column is out of a 1984 Chevy truck. I have black and green wires going to my turn signals so that's why I was saying I still have my eye on the black wire I found dangling. I'm going to try and get to this tomorrow if possible to do some more testing.

[RustyPile]

Originally Posted by Zippi

I have a 1949 Chevy 5 window truck. All the lights are aftermarket. All the wires appear to be new as this truck was built in 2015. My steering column is out of a 1984 Chevy truck. I have black and green wires going to my turn signals so that's why I was saying I still have my eye on the black wire I found dangling. I'm going to try and get to this tomorrow if possible to do some more testing.

I can help you with the wire colors at the turn signal connector at the main harness but I'm afraid anything beyond that is pure conjecture.. The black wire at the turn signal connector comes from the horn relay ground terminal and goes to the horn contact in the steering wheel.. What that black wire you found "dangling" is anybody's guess..

Here's the color code at the turn signal switch connector for the steering column----

Black - Horn relay ground to horn button in steering wheel
Lt blue - Left front turn signal and left turn indicator in instrument cluster
Blue - Right front turn signal and right turn indicator in instrument cluster
Brown - From hazard flasher
Purple - From Direction flasher
Yellow - Left rear turn signal
Green - Right rear turn signal
White - To stop light switch

You might try my test instructions in my first post.. I don't know if they will help or work for you or not.. The color code for GM vehicles of the '70s - '80s era usually follows a pattern, but there's no telling about the harness in your truck... Sorry I can't be of more help...

[Andy4639]

What I would do first. Take the wires loose at the closest spot you can from the turn signal lever. Take your test light and ground it and check each wire for power noting what position the turn signal lever is in and what the head light switch is in for each wire. Yes it will take some time but in the end you will know which wire is which. No guessing.
Here are some schematics for you and see which one matches your setup.

[Zippi]

Alright guys. Wife and I just got back from the store. What a task. Walmart has a waiting line outside and they are letting people go in one at a time and you are limited on what you can buy. We drove off and went somewhere else. Anyway when we got home I decided to track down all the wires and everything looked good with no broken connections. Ground at both turn signal housing were good so as a couple guys had suggested I went inside the cab to start probing the wires at the bottom of the steering column hoping the color code was kept the same and it was. I cut some of the insulation back on the wires I tracked down and with the engine running and the left turn signal on my test light would flash touching the wire. With my test light on the right turn signal wire my test light would come on but not flash. I think we are getting somewhere thanks to you guys. I had a steering wheel puller and got it off but there is a plate that may require some other type puller. I'm assuming the turn signal switch is under there.

[RustyPile]

Originally Posted by Zippi

Alright guys. Wife and I just got back from the store. What a task. Walmart has a waiting line outside and they are letting people go in one at a time and you are limited on what you can buy. We drove off and went somewhere else. Anyway when we got home I decided to track down all the wires and everything looked good with no broken connections. Ground at both turn signal housing were good so as a couple guys had suggested I went inside the cab to start probing the wires at the bottom of the steering column hoping the color code was kept the same and it was. I cut some of the insulation back on the wires I tracked down and with the engine running and the left turn signal on my test light would flash touching the wire. With my test light on the right turn signal wire my test light would come on but not flash. I think we are getting somewhere thanks to you guys. I had a steering wheel puller and got it off but there is a plate that may require some other type puller. I'm assuming the turn signal switch is under there.

If the bulb in the test light came on, whether it blinked or not, the problem is NOT in the turn signal switch.. No need to go into the column.. The test light didn't blink because the flasher didn't have enough load (bulb current draw) to make it flash.. Move forward toward turn signal bulbs at the front, looking for a broken wire or bad connection at a plug. A bad or missing ground at the bulb socket will give the same results.. Did the right turn indicator in the dash blink, or at least come on, during the test???

Also no need to peel back the insulation, just shove the point of the test light into the connector from the opening where the wire enters the plug..

[dmjlambert]

Originally Posted by RustyPile

... no need to peel back the insulation, ...

Agree. The test probe probably has a sharp tip. Mine does. I can poke it into plastic wire insulation at points I want to check, and the end of the tip contacts the copper wire conductor. But in most cases the method RustyPile mentioned is best, just poke into the connection in the back of the plug.

[Zippi]

No lights on the dash fellows. Well I'm glad it's probably not the switch. The only thing I saw that might be an issue was inside the right side bulb socket the two contacts seem to be all the way to one side and one was touching the bulb socket. I used a flathead screw driver and moved it over and tried the turn signal but got nothing. If it's the bulb socket that may be bad would I be able to probe the wire before it goes into the bulb socket and get my test light to flash?

[RustyPile]

Originally Posted by Zippi

No lights on the dash fellows. Well I'm glad it's probably not the switch. The only thing I saw that might be an issue was inside the right side bulb socket the two contacts seem to be all the way to one side and one was touching the bulb socket. I used a flathead screw driver and moved it over and tried the turn signal but got nothing. If it's the bulb socket that may be bad would I be able to probe the wire before it goes into the bulb socket and get my test light to flash?

That's exactly how it's done.. The light may not flash because the test light bulb may not draw enough current to flash... But if the light comes on, flashing or not, then I'd suspect a problem with the bulb socket or bulb.. Be sure your test light is well grounded.. While you're at it, make sure the light housing is well grounded..

Most "normal" GM turn indicators are tied in with the front turn signals.. But in your case, who knows.. If the harness in your truck follows the "normal" GM color code, the light blue and blue wires are split off into two of each.. One pair (light blue/blue) goes to the front turn signals and the other pair goes to the turn indicators in the dash.. I can't say that for a fact, but it would be the most logical layout...

[Andy4639]

Yes it should flash as long as the flasher is working. The socket should have 2 tits in the bottom. Put your test light on each one and see if one flashes. If not try a new flasher in the fuse block.

[Zippi]

Thanks guys. Sinse the battery is handy right on the passengers side floor board I'm grounding my test light right on the battery. I've replaced the bulb with a new 1157. I pulled all the tape off the wires and pulled all the wire out of the loom and it all looks good as far as I can tell. I'll give the bulb socket another look tomorrow and probe the wires before the socket and see what I come up with.

[RustyPile]

In most cases, a test light does not present enough load on the flasher to make it flash.. The OP stated in the first three sentences of his original post that all the turn signal lights flash as they should except the right front turn signal.. That indicates the flasher is in good working order.

[RustyPile]

Originally Posted by Zippi

Thanks guys. Sinse the battery is handy right on the passengers side floor board I'm grounding my test light right on the battery. I've replaced the bulb with a new 1157. I pulled all the tape off the wires and pulled all the wire out of the loom and it all looks good as far as I can tell. I'll give the bulb socket another look tomorrow and probe the wires before the socket and see what I come up with.

Using your test light check for voltage on the wire just before it enters the bulb socket. If voltage is present, suspect the bulb socket.. You already stated the socket contacts are out of alignment. Probing the contact inside the socket is not all conclusive.. It may not be making good tight connection with the bulb's contacts.. I've suspected all along that you have a bad bulb socket, or possibly it's not grounded properly...