Another L.E.D Turn Signal Problem

[nrb's70gmc]

Ive searched the web and this site, but cant seem to get a straight answer.

ive been running Regular bulb up front with led tail-brake-reverse lights for years (with a standard flaser 10+ years)

i installed led front lights and bought one of these
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

wired up the ground and no flash/blink lights (parking) are on solid

the new flasher has the same pin position as the stock one i pulled out
old flasher says (HEAVY-DUTY FLASHER FUSE INPUT LEAD)
new flaher says(HEAVY DUTY INPUT LEAD MUST BE FUSED)

Any idea's Thanks (truck = 1970 gmc)

[harpo231]

I thought needed a 3 prong

[Andy4639]

They make adapter for the flasher to swap polarity to make them work. LED are polarity sensitive where the regular bulbs are not. It could be the grounds also on the front turn signal housing not making good contact.

[nrb's70gmc]

if their were bad grounds wouldnt that prevent the parking lights from working?
my parking ligts are on solid. just dont blink.

[Andy4639]

Originally Posted by nrb's70gmc

if their were bad grounds wouldnt that prevent the parking lights from working?
my parking ligts are on solid. just dont blink.

Not necessarily. They are separate circuits but I think the problem is the polarity.

[Already Gone]

Originally Posted by nrb's70gmc

Ive searched the web and this site, but cant seem to get a straight answer.

ive been running Regular bulb up front with led tail-brake-reverse lights for years (with a standard flaser 10+ years)

i installed led front lights and bought one of these
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

wired up the ground and no flash/blink lights (parking) are on solid

the new flasher has the same pin position as the stock one i pulled out
old flasher says (HEAVY-DUTY FLASHER FUSE INPUT LEAD)
new flaher says(HEAVY DUTY INPUT LEAD MUST BE FUSED)

Any idea's Thanks (truck = 1970 gmc)

What did you wire the ground to? I have the same flasher as Andy posted and used one of the screws from the dimmer switch for ground and as Andy says the polarity has to be right for them to work properly.

[nrb's70gmc]

Originally Posted by Andy4639

Not necessarily. They are separate circuits but I think the problem is the polarity.

So I just made some short leads to test. (Flasher is plugged in opposite) still solid no blink. This is the electronic led flasher /w ground wire

[nrb's70gmc]

Originally Posted by Already Gone

What did you wire the ground to? I have the same flasher as Andy posted and used one of the screws from the dimmer switch for ground and as Andy says the polarity has to be right for them to work properly.

First ground was on bracket under steering coulum (my tach uses one of those screws for a ground also)

Tested. Solid leds

polarity is just reverseing the pins while plunged into fuse panal right?
I made some short jumper wires and switched the pins and put the flasher ground to the dimmer mounting screw.

Tested. Solid leds

[Robznob11]

Originally Posted by nrb's70gmc

So I just made some short leads to test. (Flasher is plugged in opposite) still solid no blink. This is the electronic led flasher /w ground wire

Im not sure if this is what you are refering to but the fix is to take a small screw driver or a jig saw blade works well. Un pin the two terminals from the plastic connector that the flasher plugs into and swap them. If you look at the flasher one is marked with an x. They as well are polarity sensitive. I had the issue and i could get the flasher to work with a load resistor but not with out it. Swapped the terminals on the flasher plug to the correct way and boom it worked. Also if you are running an aftermarket switchback style front turn it will also caus your issue because the current will bleed through the switch back circuit and not pull enough load for a blink unless they are well made switch back offerings. Usually you see this with the cheap china stuff.

[nrb's70gmc]

Originally Posted by Robznob11

Im not sure if this is what you are refering to but the fix is to take a small screw driver or a jig saw blade works well. Un pin the two terminals from the plastic connector that the flasher plugs into and swap them. If you look at the flasher one is marked with an x. They as well are polarity sensitive. I had the issue and i could get the flasher to work with a load resistor but not with out it. Swapped the terminals on the flasher plug to the correct way and boom it worked. Also if you are running an aftermarket switchback style front turn it will also caus your issue because the current will bleed through the switch back circuit and not pull enough load for a blink unless they are well made switch back offerings. Usually you see this with the cheap china stuff.

Please correct me if im wrong -

instead of moving the pins i made 2 wire leads (and plugged the flasher in)
(X to L not X to X) is that the same effect as what you explained?

Actually i have a reversed polarity led electronic flasher but it doesnt have the the ground lead. i baught (from super bright leds) but it didnt make them blink either

The leds are one color Amber not switch back.

[Robznob11]

That is correct if you have done that. I actually had both styles of flasher too. The one without the lead says no load bu they should say low load . Walmart has cheap load risistors. Just try one..... if rhat makes it work then you need to try another style of flasher with the strap. One thing for sure if it will work with a load resistor it is either polarity of flasher or type of flasher.

[Andy4639]

Are you sure the wires are connected right at the lights out front. Do,did they work before with the regular bulbs installed?

[Robznob11]

Some info http://www.memotronics.com/led-flashers/
Just to be clear
X=12v = power from fuse box
L=load = led

Also just to state the obvious there are 2 flashers one is turn one is haz. Try it in the hazard side. Making sure x and y are correct. The haz circ by nature has more load. In my case the strapless keep it clean would work with haz but not the turn circ. I replaced it with the ez style with ground strap and it worked.

[nrb's70gmc]

Originally Posted by Andy4639

Are you sure the wires are connected right at the lights out front. Do,did they work before with the regular bulbs installed?

Yes the regular bulbs worked fine. For years,

As far as I know with 1157 sockets bulbs can only go in one way?

[nrb's70gmc]

Originally Posted by Robznob11

That is correct if you have done that. I actually had both styles of flasher too. The one without the lead says no load bu they should say low load . Walmart has cheap load risistors. Just try one..... if rhat makes it work then you need to try another style of flasher with the strap. One thing for sure if it will work with a load resistor it is either polarity of flasher or type of flasher.

That is the style I'm trying to get to work right now (Flasher with ground wire)

[Andy4639]

Did you install the same flashers in both spots at the same time?






Here is a olde thread on mine when I installed them. Read it all the way through and you may find the answer you seek!

http://67-72chevytrucks.com/vboard/s...=525344&page=2

[nrb's70gmc]

Originally Posted by Andy4639

Did you install the same flashers in both spots at the same time?






Here is a olde thread on mine when I installed them. Read it all the way through and you may find the answer you seek!

http://67-72chevytrucks.com/vboard/s...=525344&page=2

thanks for the info, read it plus some more.
went and messed with flasher again and no go

my front side maker lights are wired to headlight halos- and i shaved my bed so no marker lights their either. (dont know of this affects anything)

noticed both green indicater lights come on (solid) in dash when i press brake pedal. (maybe something isnt grounding correctly?)

i have not had a hazerd flasher in for years and blinkers always worked (old bulbs) would this be affecting anything switching now to led's?

baught the led flasher w/ polerity adapter and tried it. same issue's

[Robznob11]

Just for giggles wire a bulb in line with the led. Im convinced its just a load issue. If the leds were wired backwards they would not light up at all. Also confirm 12v to x side of flasher

[Andy4639]

The LED's you installed are they 3 wires are 2 wires?

[nrb's70gmc]

Originally Posted by Andy4639

The LED's you installed are they 3 wires are 2 wires?

They are just the 1157 retrofits. Plugged into the stock 2 wire socket

[Andy4639]

Originally Posted by nrb's70gmc

They are just the 1157 retrofits. Plugged into the stock 2 wire socket

Ok then..Try taking a test light and seeing if it will light up on the housing by putting the clip on the housing itself not the frame and touching the probe to one of the button heads inside the housing. Check both of them if they work then you know it's either in the flashers are the lights themself.

[Robznob11]

If leds are lighting up but not blinking when plugged into the socket they are fine it has to be something else. If they dont light at all then its most likley the polarity of the bulb it self and rhe wires will need reversed. Green dash lights on dont mean anything. Need to knowbwhat the leds are doing

[nrb's70gmc]

Originally Posted by Robznob11

If leds are lighting up but not blinking when plugged into the socket they are fine it has to be something else. If they dont light at all then its most likley the polarity of the bulb it self and rhe wires will need reversed. Green dash lights on dont mean anything. Need to knowbwhat the leds are doing

The leds light up like normal parking lights. just dont blink.
1157 bulbs only go in socket one way.

looks like a wet day outside but will test with a normal bulb when i can.

the current situation is
electronic flasher (with ground lead grounded) plugged in with polerity reverser

[Robznob11]

Ok I think I may know whats going on here ( I build led tails and have had the same problem) yes you are correct that 1157 only go in one way....but gm did not wire every truck the exact same. Andy will vouch for this because he had to swap the wires on his tails. One wire is park positive, one is blinker positive, it gets the ground from the housing. If the wires on the 1157 socket are reversed then you will turn your park light to the on position, but insted of the dim side lighting up you have the bright side light up. Now when you hit the blinker (which should be hooked to the bright side) it is triggering the dim side to flash but it can not do so because the park circuit is already supplying power to the bright side.

Led turn signals work using a single led (many in a group) to run at a reduced brightness for park and full power to get brighter for the blink. Unless you have more expensive ones that usea seperate circuit to kill the park side much like a switch back. Most manufacturers take the cheaper route because for one its cheaper and 2 less circuitry to fail. There are numerous threads about led bulbs not all being the same as well dont assume because they are packages as 1157 that the polarity is correct for every vehicle its just not the case.
Hope this gets you up and going.
Also did you just reverse the flasher wires or did you confirm with a test light that X is recieving power from the fuse box. It would suck to swap wires only to find out a previous attemt to cure the issue actually compounded the problem.

Also before you cut the wires and try and swap them on the led turn the parks on and see how bright they are. Then pull the led out touch the metal end to ground and use a wire to touch power to each soulder nub separately. This will show you the difference between the bright side and dim side if the bright side looks the same as what you see when its plugged in and on park lights you have confirmed they need swapped��

[nrb's70gmc]

Originally Posted by Robznob11

Ok I think I may know whats going on here ( I build led tails and have had the same problem) yes you are correct that 1157 only go in one way....but gm did not wire every truck the exact same. Andy will vouch for this because he had to swap the wires on his tails. One wire is park positive, one is blinker positive, it gets the ground from the housing. If the wires on the 1157 socket are reversed then you will turn your park light to the on position, but insted of the dim side lighting up you have the bright side light up. Now when you hit the blinker (which should be hooked to the bright side) it is triggering the dim side to flash but it can not do so because the park circuit is already supplying power to the bright side.

Led turn signals work using a single led (many in a group) to run at a reduced brightness for park and full power to get brighter for the blink. Unless you have more expensive ones that usea seperate circuit to kill the park side much like a switch back. Most manufacturers take the cheaper route because for one its cheaper and 2 less circuitry to fail. There are numerous threads about led bulbs not all being the same as well dont assume because they are packages as 1157 that the polarity is correct for every vehicle its just not the case.
Hope this gets you up and going.
Also did you just reverse the flasher wires or did you confirm with a test light that X is recieving power from the fuse box. It would suck to swap wires only to find out a previous attemt to cure the issue actually compounded the problem.

Also before you cut the wires and try and swap them on the led turn the parks on and see how bright they are. Then pull the led out touch the metal end to ground and use a wire to touch power to each soulder nub separately. This will show you the difference between the bright side and dim side if the bright side looks the same as what you see when its plugged in and on park lights you have confirmed they need swapped��

Thanks for that I'll get back at it when the rain allows. As the original flasher the new electronic flasher has power.

In my opinion the park lights are just as bright as blinkers (based on the old bulbs setup)