Hello, I dont fequent this side of the forum much, which is probably a real mistake on my part. But maybe someone here can help. Im having a problem with my left turn signal not functioning when the headlights are on. When I do turn the headlights on, the left blinker indication light stays on all the time, and the left blinker does not function. The right side, however, works fine. I already did a search on this topic, and I found similar articles on which to base repairs on, but I would like to clairify and reinforce the suggestions. Perhaps I have missed something I need to check. I of course, have a multimeter, Haynes corvette manual, and advanced wire troubleshooting abilities. I just dont want to miss something stupid.


Here is what I should check so far, and please, tell me if I miss something:


1. Left headlamp general grounding.
2. Relay Failure / Blinker thermal trigger switch
3. Frayed ground-fault wiring (kinda hard to check, unless you pull out all of the wiring harness. )
4. Bulb assembly and lamp holder (corrosion?)
5. Corroded relay terminals

ok im out of ideas...tell me if im missing something obvious.

Also, I could measure the resistance from the blinker lamp frame ground to the battery, just for sanity.


I would appreciate suggestions!


snoopdan

 

Is one of your left front parking or rear tail lights not working too? If so try replacing that bulb (check the side marker too). The parking filiment can break and fall across the turn filiment, or the other way around, and cause this kind of problem. I'm sure you probably already checked this first, but.....

 

Your symptoms are carrying a LARGE sign saying, "THE BLINKER LAMP HAS A SHARED GROUND WITH THE HEADLIGHT AND THE GROUND CONNECTION IS CORRODED AND HAS HIGH RESISTANCE".
Your left blinker stops because the blinker works on lamp current and the ground connection has voltage on it (it should be zero volts) with the headlights on due to the headlight current through the resistance of the ground connection. This voltage subtracts from the blinker lamp which then has low current and low current will not operate the flasher, thus your left side turn signal lamp stays on when the headlights are on.

Solution: First find the chassis ground bolt, black wire to G115 which is on the frame behind LH park/turn lamp. That is most likely where your problem is. If it is ok, then follow the black wire from G115 into the wiring harness to a splice, S120, and check the quality of the splice.

 

Yes, thanks for helping. I kinda guessed that, but really its hard for me to work on my car right now. I just had my left hip replaced a couple of days ago, so i can barely walk much less hold a voltmeter under the hood and work on stuff. But thanks for the info. Ive had a pretty hard couple of months, getting both of my hips replaced, so its hard for me to do anything. I know, TMI.

 

This must be a common problem. I just got a 86 on a trade that does the same thing. Let me know what you find.

 

Go over to the Norhteast Section and see Rex Ruby mod day post, I think they fixed this problem on one of the cars that was there, pick his brain a little.

 

This is what you get for not using KaleCo's patented Synthetic Blinker Fluid.

 

I have an 86 also that had weird electrical issues.

I installed a rebuilt dash, and my turn signals worked correctly, the third brake light now works.

How's your dash?

Roger

 

My dash is acting a little funky also. For sure I have a bulb out on the tach, and at night the dash gets a little dim and flickers. But Ive never pulled the guages before, so it might be corrosion / heat failure / who knows. I do know that when I pull that **** out, i'm gonna resolder all of the traces and check for continuity of the circuits. I dread pulling all that crap out. I miss my Fiat's dash - It was all fiber optic! Only one bulb lit the enitre dash. VDO actually made the guages with the fiber optic links...pretty cool for a car in 79. I dont know why new cars dont have this !??! Its old technology! But they probably have a contract with sylvania or ge for like 100 years for providing GM lighting componants.

Also, I just had surgery to replace my hip, so im in no shape to pull a dash. UGH it sucks getting sick.


snoopdan

 

I have a similar problem:

When headlights are on, left turn indicator on dash is always on.

Front left amber bulbs never light up (front and front side).

When I hit the left blinker (whether headlights are on [i]or[/b] off) the left turn dash indicator light turns on (solid), and rear lights blink once (briefly, while the lever is being moved).

All other lights on the car function perfectly.

The previous owner of the car told me that she held the blinker lever left while turning the car right (lord knows why...), and she heard a "snap" from the column. From this point on (allegedly), the left blinker has never worked. Does this sound like a blinker module? Where is this unit located?

Cheers!

-ToDD

 

 

I normally find it's either a bad earth or 1 of the wires has broken away or corroded on 1 of the lamp holders.