Hi Guys,
I need some pointers as to an electrical issue i have with the 73 vette .

I am going to try and describe the problem and hope i dont confuse the whole thing .
When i put on the lights the left side arrow on the dash clocks illuminates and stays illuminated . The front left marker light does not illuminate nor the grill light , but the indicator lights still work with the lights , as well as operating normally without the lights selected .

Hazard lights operate if selected , and if i manipulate the hazard switch i can get the indicator arrow light to extinguish and the marker lights to illuminate with the lights on , but not very often . Horn button does not work properly and needs replacing .

Do you think the problem lays with the turn signal switch and wiring , which i will replace when the horn contact is changed , or should i look for the problem else where ? I have checked the marker lamps and the earth connections to both and all seems fine .

I appreciate its a difficult one , but maybe someone has had the same type of problem before and can point me in the right direction ??

Thanks Guys,

John

 

I think there is a problem with the electrical ground connections in your car. It is difficult to tell which circuits have grounding problems, based on your symptoms. But, when you turn on various circuits, the power signal for that circuit is finding it's ground connection via a different circuit. This causes "unexpected" lighting/function issues elsewhere.

The ground connections to check (and remove/clean/reinstall) are for the headlamps, the turn signals/marker lights, the tach/speedo [this is a black wire running from the rear of the speedo housing to the left-front door jamb frame], and the gauge cluster [ground from metal cluster panel to framework of the lower transmission console, near the ashtray].

I think if you make certain that those ground points have good integrity, those electrical problems will likely be resolved.

 

Hi 7T1 vette ,

Thanks a stack , i have the centre console removed at the moment so it should be easy for me to trace all the earth connections that you advised me to check , clean them all up and make sure they have a proper grounding .

Thanks
John

 

Hi 7TI Vette,

Just a quick reply to say thanks for putting me on the correct track regarding the wiring problem.
It took me 2 evenings of fault finding and head scratching on this one , after testing with my multimeter , and confirming all the voltages were correct as well as checking that all the earth connections you recommended were clean and tight i was getting to give up stage , especially as some of the time i could get everything working and just when i was about to pat myself on the back and go to bed the gremlin would return , no marker light on left side and no front running light Wtf !!!!!

I ran an earth wire directly from the battery and created a good earth connection to the front running light voila all ok , so where was my problem ?? I pulled off the harness extension wire and tested the supply at the plug , all was ok , now i was at a loss . I went into the house and threw the extension onto the coffee table and went to pour a beer , (damn hot in the garage right now ) when i got back beer in hand i sat down and picked up the harness and my tester , checked the continuity of the wires and guess what , ground wire continuity was missing , i had my problem !!!!!

Looking at the back of the globe holder the ground or earth connector is the one on ots own that goes to the ring that surrounds the globe body and the part that the pins of the globe lock into . This connection can be taken out of the holder , its really very poor in the aspect of a definite connection , as it relies on the very small end of the brass tag pushing against the metal ring inside the holder . I could clean it up and push it back but have ordered new units as they come in pairs .

So guys if you ever have a solid flicker light indicating on your instrument panel when you select your headlights , and you see that the front lower running light and the marker light is not illuminated , go straight to the extension harness first , its in all the elements of water , salt and grime , take it off and pull the black wire out of the holder and make sure it and the holder ring termination is clean , it might not cure your problem but you will know you have to look deeper into your problem , but i think that more times than most you will find a poor connection at the lamp holder and should cure the problem faster than i did.

Thanks again 7T1 vette

You Guys Rock

Cheers,

John