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4.3 Volt instead of 12 Volt (1/5)
 9/29/19 2:32pm
Christian
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Houston, TX - USA

Vette(s):
1971 LS5 Convertible 4 sp


Joined: 2/25/2003
Posts: 181

My first reaction when I noticed the front left side marker was not working while the other three were, was to change the bulb. No luck. So I tested the bulb with an independent 12-volt source: It worked. Then I measured what I get at the socket: 4.3 Volt. Same just before the socket. So, it is not the bulb nor the socket. I can't really follow the wires up as they disappear into the wrapped harness to the firewall.

Any advice on how to proceed from there?



|UPDATED|9/29/2019 12:32:07 PM (AZT)|/UPDATED|
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Re: 4.3 Volt instead of 12 Volt (2/5)
 9/30/19 12:38am
73shark
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 605

I suspect that ~8 volt drop is occurring at a corroded pin in a connector on the other end of the harness. 



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1973 L-82 4 spd

Re: 4.3 Volt instead of 12 Volt (3/5)
 9/30/19 6:37am
Christian
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Houston, TX - USA

Vette(s):
1971 LS5 Convertible 4 sp


Joined: 2/25/2003
Posts: 181

For only one of the two front side markers? All other lamps work fine.

Where do I find this connector?

Re: 4.3 Volt instead of 12 Volt (4/5)
 9/30/19 9:58am
73shark
Standard Member
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 605

You really need a copy of the wiring diagram to find out if and where that connector is. Some of the aftermarket Corvette suppliers sell just the wiring diagram by itself or you can get it in the factory service manual. I would also check the socket for any evidence of corrosion. You could physically follow that wiring harness back to see if you can determine where it terminates.



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1973 L-82 4 spd

Re: 4.3 Volt instead of 12 Volt (5/5)
 9/30/19 8:32pm
Adams' AppleLifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas


Joined: 11/8/2003
Posts: 19688

Once again...I have all of the '68-'82 Corvette wiring diagrams on my web page. Download or view on-line, either way....

'71 Corvette Wiring Diagram



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Joel Adams
C3VR Lifetime Member #56    

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