Re: LED turn signal issues
 

My 71 has all LED in it. No problems at all with anything. Everything works like it's suppose to. Both flashers are LED with grounds. No need for the old bulbs to be put in at all. Just fix the wiring so it's right.:chevy:

https://www.youtube.com/watch?v=KEwca2XGBVM&t=6s


https://www.youtube.com/watch?v=TxGB0TewBqU


https://www.youtube.com/watch?v=XIOwg83B9Fg

Re: LED turn signal issues
 

Andy4639 the problem I’m having is when I turn on my headlights the rear turn signals don’t work and the tail lights get bright. I added 2 new grounds from the frame to the bed. All my wiring is new.

Ramiro

Re: LED turn signal issues
 

Then I would think your new wiring is not correct. You wouldn't be the first to have a wire crossed. The LED lights do not like crossed up wires.:chevy:

Re: LED turn signal issues
 

My wiring was absolutely fine and I had to add a dummy plug to get the brake lights to operate correctly. I had the same exact problem. The dummy plug fixed it. It’s that or putting resistors in. I’m pretty sure it was the brown and yellow wire. I tapped in to the intermediate rear harness. Right before the plug. Make sure you put a good bulb in it and then be sure to cover the bulb.

Re: LED turn signal issues
 

jessethompson I received the polarity reverse adapter today. I've added it and it did not make a difference. I guess its time to add dummy plug. Could the dummy plug be a plug for the side markers?

Thanks,
Ramiro

Re: LED turn signal issues
 

Here is what I think you have going on. Tail and brake lights are supposed to work like this when you have a conventional bulb. The bulb has 2 filaments. One of the pads on the bottom of the bulb is for power supplied to a very dim filament, that is used for when your headlights are on. It is the running light or parking light. The other pad on the bottom of the bulb is for power supplied to a very bright filament. That is for brake or turn signal. So, if you have brake applied and while your brake is applied you turn on the headlights, you will notice almost no difference in brightness. That is because you are adding something like 2% more brightness to a bulb that is glowing at 98% brightness already because you have the brake applied.

So now imagine what would happen if the filament connections were reversed. You get a very bright running light because your headlights are on, and if you use the turn signal or apply the brake, it only gets 2% brighter. You probably wouldn't even notice the difference. Especially in the day time. I see a huge number of tail lights in cars that people have modified from factory, especially Jeeps for some reason. A large number of LED lights come from the manufacturer's wired backwards if they have a bulb base wired onto them. And if they are hard wired by the person making the "upgrade", that person just doesn't pay attention.

The knobs on either side of the base of the bulb plug are at different distances or heights from the bottom of the base where the contacts are. That is supposed to keep you from getting the bulb in there backwards. But if the bulb is made wrong, or if you force the base into the socket backwards, either of those conditions can cause the problem. Somebody helping my daughter with bulbs did that to her car, forced the bulb in the wrong way. It cracked the socket because the socket was plastic, and I did not appreciate that and had to repair it. But the filaments were reversed and it had the symptom I describe.

I see Jeeps in my area all the time that have LED lenses where the dim outer ring of LEDS is supposed to be for running light, and the bright inner spot of concentrated LEDS is supposed to be for braking, but they have it wired in reverse. The running light is bright as heck when following one of those guys, and if they apply the brake and that dim outer ring of LEDs come on, I can barely tell, unless I'm paying close attention.

Here is how to troubleshoot and resolve. Remove an LED light and take it to a bench with a battery or to the front of the truck. Use alligator clip test wires. Connect the negative battery post to the base of the bulb. Connect the positive battery post to a test clip wire and tap the other end to one of the 2 contacts at the base. Figure out which contact makes the bulb grow very bright, that is your brake and turn signal filament. Tap the positive test wire to the other contact on the base and very it glows but not nearly as bright. That is your running light. Use a marker to mark which is which. Go to the tail light socket on the truck. Use a test light or multimeter to figure out which of the 2 pads at the bottom of the socket gets power when headlights are on, and which get power when brakes are applied. Mark which is which. Then verify the correct contact on the bulb is engaging the correct contact in the socket when you insert the base and lock it into place.

It is also a good idea to make sure the truck works with conventional bulbs before trying LED bulbs. You may have done that already.

I think a lot of LED bulbs are made incorrectly and both of the "filaments" glow at the same brightness. In my opinion, those are cruddy. The ones that have different brightness filaments but are wired to the base pads backwards are extra cruddy.

Anyway, sorry that was such as long story. If it leads to resolving the problem, great. If it does not, then I'm sorry, but perhaps the troubleshooting ideas and thoughts will help somebody.

Re: LED turn signal issues
 

Thanks dmjlambert, I will try that also.

Ramiro

Re: LED turn signal issues
 

jessemthompson, Cover the bulb with tape?

Thanks,

Ramiro

Re: LED turn signal issues
 

dmjlambert, I tested the LED light like you advised. I found which connection was the brightest. In the socket of the taillight housing it corresponds to the correct one. I installed regular light bulbs and you could see the light blink. But its very faint. The rear tail lights are just too bright to see it blink when the head light switch its on. I tried a new turn signal switch and headlight switch and I still have the same results. Not sure what to do now. This is ready getting me frustrated.

Ramiro

Re: LED turn signal issues
 

These are $6 bucks from Amazon.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
I have LED's in Otis my avatar and my 40 coupe, the 40 coupe was the learning curve I tried every flasher made for LED's and nothing worked.

I finally broke down and got a hold of one of my sons high school buddy's who became an Electrical Engineer.....he sent me this said throw all those flashers in the sh*tcan and install these.

Everything worked perfectly after I put these in, no regrets....you could have other problems but it sounds like you've covered your bases.

Re: LED turn signal issues
 

Sheepdip, I will order them to give them a try. I have tried everything possible. Everything works fine until I turn on the headlight switch. Also do I connect the wires from relays to the yellow, green and brown wires?

Thanks,
Ramiro

Re: LED turn signal issues
 

Two things I don't understand:
1. load resistors are about getting the flashing module to actually flash. They are not related at all to how bright or dim an LED light glows. So if there is flashing going on but it is just too dim to notice compared to the tail light, why are we talking about load resistors? If I am mistaken please let me know.
2. If the tail light is what is very bright, and the turns signal or brake is only slightly brighter, isn't that exactly what I was talking about being wired opposite and that would indicate wiring or the bulb base or socket is wired backwards? I am talking about post 31 above. You respond "I found which connection was the brightest. In the socket of the taillight housing it corresponds to the correct one." What is "correct one" and let's be clear. The correct connection for the brightest LED is the brake/turn contact, not the tail/running light contact. If your LED has separate contacts and one is less bright than the other, and you ensure the less bright contact is used for tail/running light, then I don't see how you can't resolve the issue.

And one comment: If you have a conventional bulb and it behaves the same way as your LED bulb that indicates the truck wiring is backwards, and the bulb base of the LED is not at fault.

Re: LED turn signal issues
 

I'm no expert nor do I profess to be, I'm simply stating my experience and what resolved the issue. Just trying to give another option to help the gentleman hopefully resolve his issue.

Re: LED turn signal issues
 

The wires coming out of the load cells have no polarity, splice one into the positive or 12 volt side and the other into the ground side preferably close to the LED bulb but not required. Make sure, and I think you have that your grounds and bulb contacts are good.
Put your original flasher (known to be good) back in place. This is how I did it and it solved my non flash issue. I hope it resolves your issue for you.

Re: LED turn signal issues
 

Dmjlambert, when I troubleshooted like u advised me. When I tested the LED light at the battery. One of the connections on the bottom of the LED light socket was britghter than the other one. When I went back to the tail light housing . I verified which one was the contact in the tail light housing when the headlight switch was turned on. It corresponded to the contact on the LED socket that was the brightest when I tested it at the battery. Unless I did something wrong when I tested it. Maybe I should switch the yellow and brown wires around to see if that changes anything.

Ramiro

Re: LED turn signal issues
 

There you found the problem! The contact on the LED socket that was the brightest when tested at the battery should not connect to the tail light housing contact that gives voltage with the headlight switch on.

It should connect to the tail light housing contact that gives voltage when the brake is pressed.

The contact in the tail light housing that gives voltage when the headlight is on should connect with the dim LED.

Re: LED turn signal issues
 

[QUOTE=dmjlambert;8810880]There you found the problem! The contact on the LED socket that was the brightest when tested at the battery should not connect to the tail light housing contact that gives voltage with the headlight switch on.

It should connect to the tail light housing contact that gives voltage when the brake is pressed.

The contact in the tail light housing that gives voltage when the headlight is on should connect with the dim LED.[/QUOTE

Dmjlambert thank you for your help. Lights work correctly now. Had to switch the wires around . Also thank you all that commented on the post to help me out. I greatly appreciate it. Thanks again .

Ramiro

Re: LED turn signal issues
 

Wow! Kudos to everyone for the amount of help offered up in getting this issue resolved for the OP! That's something that I find quite impressive on this site.....the simple desire to help a fellow enthusiast when in need.

This will all be very helpful information, as I am looking into changing everything over to LED's for brighter lighting. Especially with the headlights. At least I hope it'll make a brighter difference with the headlights. LOL

I do have concerns as to whether the original wiring harness can handle the change or if I will have to make plans to change to a new harness. What kind of experiences/opinions do you guys have? Did you have these issues with the original harnesses or was it on new systems or was it an issue with both?

Greg

Re: LED turn signal issues
 

I agree, this thread is very helpful. I have all my LED lights, including new LED Headlights, on my workbench for when my truck returns from East Texas (A/C has become a $$$ hole).

@Ashx2 - I actually decided to change the harnesses out without even trying it with the old one. It's a replacements with uses the original power from the switch to turn on +12 from the battery via relays. More power I say is better for HeadLights! ha!

Re: LED turn signal issues
 

LED lights draw less current, so you could actually use smaller wires. Proof of that is that when you put in LED lights for stop and turn signals, the flasher element doesn't get hot and won't flash. It takes an electronic flasher which triggers via a timer.

Re: LED turn signal issues
 

Greg I replaced all the wiring with a kit from American Autowire. All the wiring is new from front to back.

Ramiro

Re: LED turn signal issues
 

I bought a new set of LED lights for my golf cart. I bought 32 ford tail lights though. So the instructions show the white wire as ground, black is stop lights and turn signals and the red wire is running lights.

This is totally different than most auto wiring setups.

Normally black is a ground red is 12 volts positive and white is for turn signals are other lighting.
Just some info for wiring up LED, not sure if there is a uniform wiring but it may shed some light on this.:chevy:

Re: LED turn signal issues
 

Well, I got my United Pacific LED installed all around, all worked perfectly. For my front side blinking markers this post by 9teen69 made it a SNAP!

http://67-72chevytrucks.com/vboard/s...5&postcount=12

Re: LED turn signal issues
 

I've got a strange one for you. Rear are LED, Fronts are still reg bulbs. Everything worked OK, but flashed a little to quick on the turn signals. Put the UP led flasher in had to reverse the leads, works great. Now on to my 4 ways. with the old flasher unit in works great, hit the brakes and quits flashing. This is normal to my thinking as if your driving down the street with 4 way flashing and hit the brakes you want to signal someone you are stopping. Put the UP led flasher in and works OK until you hit the brakes. Continues flashing but real quick like, almost as if brakes are 80% bright and 4 ways move it up to 100% For now I left the standard flasher in