Turn Signal / Brake light issue

[C5Volzfan]

Okay, here is what I have:

I installed the halo style LED taillights over 5 years ago, along with ballast resistors. Never had a problem until now. Front light bulbs are regular bulbs.

Now this is my issue.

Headlights/Parklights off:
All turn signals work normally (dash indicators work fine also)
Brake lights work normally (HMSL works fine also)

Headlights/Parklights On:
Front signals work normally
Dash indicators work normally
Right Rear Signal works
Left Rear Signal DOES NOT work (both lights seem to dim and "flicker" a bit while front flashes)
Brake Lights DO NOT work (except HMSL - it works fine) If anything, the brake lights seem to dim a bit

Pretty sure it's a ground issue, but where, and why all of a sudden? Car is garage kept, driven about 4k - 5k per year.

Any ideas? Thanks in advance for any and all input!

John

 

[dadaroo]

I don't normally bother with LED issues but-

You have an issue with your left side LEDs.

Something that affects both of them (2).


All the lights in the back go to one ground so forget trying to chase that rabbit down the hole.

The fact that you have issues when using the brakes is because you are powering the left and right brake lights at the same time via one circuit. That makes the left affect the right side performance.


Mr. Sam

 

[C5Volzfan]

Mr. Sam,

Thank you for your response. You very well could be correct, and I can check this pretty easily by removing the LED units and plugging in the OEM bulbs, so I will do that, hopefully tomorrow night after work. The only reason I've not already tried this test, is because I assumed that if it were the LED unit that it would not change when the headlights/park lights were on. It does work fine when they are off.

The lights "act" just as if there is a bad ground.....we've all seen trailer lights with a bad ground and how they seem to do the opposite of what they should.

I'll post my results once I try the old bulbs. Thanks again for taking the time to respond!

John

 

[dadaroo]

I really don't think it is anything with the multifunction switch on the column. I can provide all the schematic information if needed later.

Swapping to OEM bulbs is a good first start in diagnostics.


Mr. Sam

 

[C5Volzfan]

Mr. Sam,

The very first diagnosis (I should have mentioned this in my first post....sorry) from a local shop was the multifunction switch. I don't guess I have to tell you much more. A new (AC Delco) multifunction switch had no effect on the problem, so you are correct in that assessment.

Once again, I'll change out the bulbs tonight and let you know what happens.

Thanks again for your time!

John

By the way, are you a member of the Corvette Club in Columbia? We met several members of that club a few years ago in Maggie Valley, NC. Just wondering.

 

[dadaroo]

Yeah, too bad about the MF switch but it can be a bad actor so it was not totally wasted money.

Not a member here but I guess I need to look at when they meet again. I was going to attend way back but they apparently canceled the meeting.


Keep me updated. I've worked on dozens of lighting issues with success.


Mr. Sam

 

[C5Volzfan]

Mr. Sam,

Ended up working late last night, so I didn't get a chance to change the bulbs. I'll try to get to it tonight.

I do have a question. When you turn the lights on, do the taillights still use the same ground? I seem to remember that on an old C3 Corvette I once owned that the polarity changed when you turned on the headlights/taillights, and that changed the ground side of the multi-element bulbs. I could be remembering wrong, though.

John

 

[dadaroo]

Everything (lights) in the rear uses the same ground. All the grounds go into a splice in the trunk and then go back thru the same connector that provides the power. Everything goes to one ground stud o the left rear frame rail.


Mr. Sam

 

[C5Volzfan]

Okay, removed the LED units, installed 4 new 3057 bulbs, and it works just like it should. So, thanks so much.....you were correct. I guess that there is something wrong in the circuitry inside the lights. I still have the original taillight housings, so I will just re-install them for now.

I really like the LED lights.....I like the fact that they are brighter (which seems safer to me). I suppose I will have to replace them if I want them.

Thanks again for your help, and I hope we cross paths somewhere so I can shake your hand and thank you properly. We went over to the Vettes for Vets show in Forest City, NC last May, and we might do that one again. Do you by chance go to that show? I also know a group from Columbia usually go to the Corvette Corral at the Rolex 24 in Daytona, and we are going there again later this month.

Again, thanks for offering your time and knowledge. Corvette folks are the best!

John

 

[dadaroo]

Glad you found the issue. Let me know if you ever have an issue and I don't see it. I am across 5 different Forums.


Mr. Sam