Having problems with blinker

[PhotonFanatic]

Hi all. I'm having some trouble with my blinker, which is preventing me from getting the required state inspection sticker. For some reason, my driver's side blinker will only work if the headlights are off. If I turn them on, that side won't blink. 87 Silverado.

When the headlights are on, I'm also getting the "check your blinker" signal. This means that the green blinker indicator in the cab stays lit up at all times. Instead of just flashing when the blinker is turned on. The truck sat in the garage for 4 months, but before that everything worked fine. Anyone ever had this problem, or have any idea what's causing it?

Here's a little more detail: I replaced the ground wire, and that fixed it temporarily. Now the problem is back. The plug was old and crusty looking, so I replaced that too. No effect. I've used LED's all throughout the truck for over 5 years. Always worked fine. But it's worth noting that when I place an incandescent bulb in the socket, this problem disappears. Still, I need to fix it so that it doesn't eventually stop working even with an incan bulb.

Any help would be greatly appreciated!

 

[Redfish]

If it works with the incandescent your LEDs may be going bad. My advice would be to replace the old LEDs or go back with incandescents.

If you haven't done it, install the Sylvania LED resistor kit. It makes a big difference.

 

[Curt]

Check radiator core support grounds.

 

[Backfoot100]

Have you tried adding blinker fluid???

 

[SirRobyn0]

@PhotonFanatic I've said this about a zillion times on the forum. If a rig comes into the shop with a lighting problem and has LEDs installed in it, the first thing we'd do is pull the LEDs and install incandescents 99% of the time that fixes the problem. Here are some quotes from other folks from a recent LED thread.

This was more about the fender light if I remember correctly but you might still find the info useful.

Why LED’s may not work well in GM fender marker lights:


First you need to understand that the fender 194 bulbs do not have a dedicated ground. One contact is wired to the positive parking light wire, the other contact to the respective turn signal wire, (right or left).


This is how they work without a dedicated ground: If the turn signal is off and the parking lights are on, current from the parking light wire through the 194 bulb then follows the other wire to the turn 1157 bulb. Current moves through the turn filament of the bulb to ground. The 1157 bulb does not light because the filament requires more current than the 194 bulb lets through. The same is true if the parking lights are off and the turn signal is on, the parking light filament becomes the ground. So if the parking lights are on, then you turn on the signal, the 194 bulb blinks off, and both contacts of the 194 bulb have current and no ground.


So of course the side marker will never work if the 1157 bulb is removed or burnt out or have a bad ground. Keep in mind at this time current can be moving in either direction in the 194 marker bulb.


Electricity 101: What is an LED? = Light Emitting Diode. What is a diode? Many kinds of diodes but we’ll keep it simple. A diode is a check valve, only lets current flow in one direction. So how can a 194 replacement LED bulb even work? Current needs to flow both ways? The bulb has a transistor!


What is a transistor? The simple definition is it is an electronic switch. The switching transistor has four connections, two from the bulb socket contacts, the other two connections to the LED. The transistor senses which way the current is flowing and directs it to the proper connections of the LED. This transistor in the 194 LED replacement bulb is very small. The transistor originally thought to be needed only a few times, depending which way the non polarized 194 bulb was installed.


So when used in a GM fender application that transistor is switching all the time. The transistor only signed up to switch a few times. Now it is switching way more and it says, “I didn’t sign up for this, I’m out of here...”

Any questions?

Below: Another long time mechanic that doesn't like LEDs

LED's sound like a good idea but they are more of a problem than a solution. An LED lamp is basically a computer circuit. They don't like poor connections or any resistance. These older vehicles were not designed to have a "clean" enough circuit. I have been able to dependably use them on clusters and side markers that have 194 bulbs, that's it.

Sockets for 1157 or 1156 bulbs won't provide a good enough contact. Some of you may disagree but that has been my experience.

Obviously, I know some guys do run LEDs successfully, but the easy solution seems to be not to run LEDs or to remove them if you are. I'm sure this isn't the answer you're looking for but it's what I got.

 

[PrairieDrifter]

Leds run fine no problems. Your wiring and grounds have to be in proper shape, and you'll need a led flasher relay, actually get two, one for the flasher one for the hazards, sometime you don't need one for the hazards.

Granted the only led "bulbs" I'm running are in my instrument cluster and inside the truck. The rest of my leds are manufactured panels. I have the sequential and rapid flash taillights as well.

Ive had zero issue in about 5 years now.

 

[PhotonFanatic]

If it works with the incandescent your LEDs may be going bad. My advice would be to replace the old LEDs or go back with incandescents.

If you haven't done it, install the Sylvania LED resistor kit. It makes a big difference.

Unfortunately this is not the problem, as I have used LED's for 5 years with no issues. As far as I know every light in the truck is an LED including the headlights. This is the only one giving me trouble. I also bought a new LED for that socket. I even switched it out with the other passenger side's LED, which is working fine.

 

[PhotonFanatic]

Leds run fine no problems. Your wiring and grounds have to be in proper shape, and you'll need a led flasher relay, actually get two, one for the flasher one for the hazards, sometime you don't need one for the hazards.

Granted the only led "bulbs" I'm running are in my instrument cluster and inside the truck. The rest of my leds are manufactured panels. I have the sequential and rapid flash taillights as well.

Ive had zero issue in about 5 years now.

Same here. No issues in 5 years until recently, but I'm just using the flashers that came with the truck. Do you think a flasher could have died? That would be confusing, because it works when the headlights are off, and there's no problems with the passenger side.

Does anyone happen to know where the headlight ground is? I've heard it can cause this problem, if that ground needs cleaned up.

 

[PhotonFanatic]

Well in case anyone else has this trouble, looks like there's two answers:

You can install a resistor that makes it the same as an incan:

Load Resistor 50W 6RJ 6ohm LED Decoder FIX Hyper Flash Turn Signal Blinker | eBay

Find many great new & used options and get the best deals for Load Resistor 50W 6RJ 6ohm LED Decoder FIX Hyper Flash Turn Signal Blinker at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Or you can replace your blinker flasher with an "electronic" one that's made for LED's. And you have to avoid the junky chinese ones. So this would be a good one:

44810 - 2 Pin Flashers, 10 Light Electromechanical

Grote Industries - Part: #44810 - 2 Pin Flashers, 10 Light Electromechanical. Bulk Pack

www.grote.com

 

[sdewolfe]

The answer posted by SirRobyn0, above, has a logical answer that fits the symptoms -- the transistor circuit in the side marker LED package has likely failed. It was working for 5 years without the add-ons. Replace the side marker 194LED before spending money and time on flashers and resistors. If the 194LED fixes the problem, plan on replacing all four corners.

 

[Royal Sierra 454]

I would check the bulkhead at the firewall. Make sure the 3/8" bolt is tight. I was having some issues with my blinkers this week. Thanks to the man above. Tightened the bolt and all of my issues went away.

 

[PhotonFanatic]

Got it resolved, it was a compound problem. First it was the ground. Then the side marker light died just while sitting there. Last I checked it was working, which was recently when I was working on the ground problem. It would light up, but with somewhat questionable brightness. Once replaced with a new LED, it got notably brighter and the problem is solved. Bad blinker signal is gone so now the truck will pass inspection.

Thanks to everyone for the help it is much appreciated!!