Headlight issue sometimes 2 lights 3 lights?
Thread Starter
Instructor
Joined: Dec 2014
Posts: 101
Likes: 0
Headlight issue sometimes 2 lights 3 lights?
Went to get my 79 vette inspection. Low beam (outside) on passenger side not working. Blinkers won't work with headlights are on but sometimes will. Blinkers are fine with no headlights on. Replaced passenger side headlight and now the driver side light won't come on. When I turn on bright lights both passenger side come on but none on driver side. Could this be the light switch or is there some goofy wiring issue? Hope one of you have had this issue and can help.
Thanks
Thanks
Pro
Joined: Nov 2016
Posts: 729
Likes: 118
From: Kelowna British Columbia
Sounds like you have a ground issue. or sockets. I had these kind of problems and with lights on turn signals were looking for a ground and used them.
I would check and clean all connectors (pigtails) and also take off ground wires clean file contact area and re attach.
I would check and clean all connectors (pigtails) and also take off ground wires clean file contact area and re attach.
Melting Slicks
Joined: Feb 2017
Posts: 3,232
Likes: 1,232
From: PHX AZ
Went to get my 79 vette inspection. Low beam (outside) on passenger side not working. Blinkers won't work with headlights are on but sometimes will. Blinkers are fine with no headlights on. Replaced passenger side headlight and now the driver side light won't come on. When I turn on bright lights both passenger side come on but none on driver side. Could this be the light switch or is there some goofy wiring issue? Hope one of you have had this issue and can help.
Thanks
Thanks
find a nice clean bolt on the chassis near the nose....hook up a ground wire to that bolt.
NOW find the ground wire from headlight etc and make a connection....if the light comes on....BINGO! BULB LIGHT!
Funny story (I've seen it ALL). Neighbor has a Mercedes (antique)....He calls me up and says HALP! I replaced ALL the lights in the car...now all the rear lights won't come on...I take out a rear brakelight bulb and it's SLATHERED in dielectric silicone grease. I say genteely WTF? He says my mechanic told me it was a good idea, so I told him to do it.
I say....the bulb has no ground...DI-ELECTRIC mean 'resists electric flow'... he spent a DAY clean that crap off of the bulbs.
good luck! Unckahal
Melting Slicks
Joined: May 2015
Posts: 2,365
Likes: 428
From: Cape Girardeau Missouri
For some reason the front park/turn lamps on a '79 are on a pigtail attached to the main harness. They are not a weather-resistant connectors and get quite corroded after decades. The connectors on the harness side are not easy to clean with the harness installed but it can be done.
There are three other chassis grounds for that "front lamp harness": One is at the alternator. Another is at top-center of the front cowling between the headlamp door vacuum relays. The final (hardest by far to access and probably the one in most need of cleaning) is on the lower-left corner of the radiator support.
After cleaning those grounds do yourself a favor and also clean the rear lamp harness ground near the radio antenna lest you begin to have bizarre electrical malfunctions!
There are three other chassis grounds for that "front lamp harness": One is at the alternator. Another is at top-center of the front cowling between the headlamp door vacuum relays. The final (hardest by far to access and probably the one in most need of cleaning) is on the lower-left corner of the radiator support.
After cleaning those grounds do yourself a favor and also clean the rear lamp harness ground near the radio antenna lest you begin to have bizarre electrical malfunctions!
Melting Slicks
Joined: Feb 2017
Posts: 3,232
Likes: 1,232
From: PHX AZ
Furthering what Mike said.
Bulb holders are FINITE...most were silver or 'gold' zinc di-chromated. Any zinc deposit
like galvanization is by design and nature SACRIFICIAL...meaning over the years it 'tries' to protect against corrosion but slowly and surely gives up the ghost. Once that's gone rust sets in. Everything must be clean shiny and bright.
If you're a boat guy...the Zinc Anodes on your engine/outboard do the exact same thing they protect against galvanic corrosion.
Galvanic corrosion is corrosion that is initiated by moisture and electricity pulling ions out of the metal/ a little bit of acid and it corrodes. Usually it is made much worse by many dissimilar metals.
good luck. UNKA
Bulb holders are FINITE...most were silver or 'gold' zinc di-chromated. Any zinc deposit
like galvanization is by design and nature SACRIFICIAL...meaning over the years it 'tries' to protect against corrosion but slowly and surely gives up the ghost. Once that's gone rust sets in. Everything must be clean shiny and bright.
If you're a boat guy...the Zinc Anodes on your engine/outboard do the exact same thing they protect against galvanic corrosion.
Galvanic corrosion is corrosion that is initiated by moisture and electricity pulling ions out of the metal/ a little bit of acid and it corrodes. Usually it is made much worse by many dissimilar metals.
good luck. UNKA
Thread Starter
Instructor
Joined: Dec 2014
Posts: 101
Likes: 0
Furthering what Mike said.
Bulb holders are FINITE...most were silver or 'gold' zinc di-chromated. Any zinc deposit
like galvanization is by design and nature SACRIFICIAL...meaning over the years it 'tries' to protect against corrosion but slowly and surely gives up the ghost. Once that's gone rust sets in. Everything must be clean shiny and bright.
If you're a boat guy...the Zinc Anodes on your engine/outboard do the exact same thing they protect against galvanic corrosion.
Galvanic corrosion is corrosion that is initiated by moisture and electricity pulling ions out of the metal/ a little bit of acid and it corrodes. Usually it is made much worse by many dissimilar metals.
good luck. UNKA
Bulb holders are FINITE...most were silver or 'gold' zinc di-chromated. Any zinc deposit
like galvanization is by design and nature SACRIFICIAL...meaning over the years it 'tries' to protect against corrosion but slowly and surely gives up the ghost. Once that's gone rust sets in. Everything must be clean shiny and bright.
If you're a boat guy...the Zinc Anodes on your engine/outboard do the exact same thing they protect against galvanic corrosion.
Galvanic corrosion is corrosion that is initiated by moisture and electricity pulling ions out of the metal/ a little bit of acid and it corrodes. Usually it is made much worse by many dissimilar metals.
good luck. UNKA
Melting Slicks
Joined: Feb 2017
Posts: 3,232
Likes: 1,232
From: PHX AZ
MWM3006...Yes, absolutely. Remember this is a CIRCUIT....you may have perfectly good volts (size of hose) amps (pressure in the hose) and Ohms (internal resistance of the hose/ viscosity..so to speak) but if you have too much resistance (ohms) on the RETURN/Ground side...electricity takes the line of least resistance....flows thru some of the lights, but not others.
You need both the current IN side and the current out side of the circuit to be NOT RESTRICTED.
Unkahal
You need both the current IN side and the current out side of the circuit to be NOT RESTRICTED.
Unkahal
Last edited by L-46man; Nov 29, 2017 at 11:24 AM.
Thread Starter
Instructor
Joined: Dec 2014
Posts: 101
Likes: 0
MWM3006...Yes, absolutely. Remember this is a CIRCUIT....you may have perfectly good volts (size of hose) amps (pressure in the hose) and Ohms (internal resistance of the hose/ viscosity..so to speak) but if you have too much resistance (ohms) on the RETURN/Ground side...electricity takes the line of least resistance....flows thru some of the lights, but not others.
You need both the current IN side and the current out side of the circuit to be NOT RESTRICTED.
Unkahal
You need both the current IN side and the current out side of the circuit to be NOT RESTRICTED.
Unkahal
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Melting Slicks
Joined: May 2015
Posts: 2,365
Likes: 428
From: Cape Girardeau Missouri
Melting Slicks
Joined: Feb 2017
Posts: 3,232
Likes: 1,232
From: PHX AZ
