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1967 No Headlights- very strange cause

Started by MikeLawson, May 05, 2019, 11:06:45 AM

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MikeLawson

I just finished up repairing my ignition switch problem and I decided to check that all electrical systems were working OK. Everything was perfect until I tried the headlights, they were MIA. Oh man, not something else to fix now.

I unplugged the  connector from the light switch and found there was no power present. I connected a battery charger to the light switch and the headlights all worked so at least I knew that part of the circuit was fine. The headlight power comes directly from the battery terminal on the starter solenoid through a fuseable link. It seemed entirely possible that the link had failed so the next step was to go under the car and check it out. The fuseable link was good so it looked like there would not be an easy solution.

The headlight power wire is inside a harness that passes through a grommet in the firewall and terminates in a connector buried under the dashboard. After some searching, I found the right connector and disconnected it so I could check for continuity to the starter. While looking at the connector I noticed that the pin for the headlight power wire was backed out of the connector body by about 1/4" inch. I can't figure out how it worked for 52 years and all of sudden it didn't.  I checked the wiring diagram and found that the 12v supply to the ignition switch also comes through the same connector as the headlight power. I think the terminal for the headlight power wire may have never been properly seated in the connector body and when I worked on the ignition switch it got pulled out a little bit more because was necessary to tug on the wiring harness to remove the switch. A classic case of solving one problem creates another.

I got the pin properly seated in the connector, reassembled everything and headlights are now working fine. What a pain!




Varooom

That is strange.  Thanks for the tip!
Happy Motoring!
1967 Cadillac Eldorado
1949 Buick Roadmaster 76S
1949 Roadmaster 76C
old favorites: 1967 Eldorado (tan), 1983 Sedan DeVille, 1977 Lincoln Continental, 1962 Chevy Impala, 1969 Lincoln Mark II, 1973 BMW Bavaria, 1972 BMW 2002tii, 1968 BMW 1600, 1952 GMC Pickup, 1953 Mercury Monterrey, 1956 Ford Victoria

savemy67

Hello Mike,

52 years ago, I am sure the wiring harness, connectors, and grommets were all a lot more flexible than they are today.  Come to think of it, 52 years ago I was a lot more flexible than I am today, which is why it is such a pain to contend with these types of wiring/connector issues.  Good work.

Christopher Winter
Christopher Winter
1967 Sedan DeVille hardtop