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68' headlight electrical problems

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Old 10-22-2013, 11:14 AM
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speedybmc
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Default 68' headlight electrical problems

I am having an issue with getting my headlights to work correctly. The issue i am having is when low beam is on the outside lights are bright as normal and the inside are dim. When high beam is on, its the opposite, High beam is bright and the low beam bulbs go dim. I checked my grounds and they are good. Is this normally how the headlights operate on these cars? Any advice would be great.

Edit: Its almost like it is back feeding at the lamp/bulb. I did a test, While low beam is on i can unplug the low beam plug from the light and the dimmed high beam light also goes off. So This lets me know the low beam hot is back feeding back into the high beam wire at a lower voltage, same with the high beam. Not sure why this is. Any ideas?

Last edited by speedybmc; 10-22-2013 at 11:43 AM.
Old 10-22-2013, 11:31 AM
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MelWff
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The inside should not be on when on low beam. Check the wiring at the switch on the floor for any corrosion or melted wires. You could try replacing the switch.
Old 10-22-2013, 03:28 PM
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speedybmc
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Originally Posted by MelWff
The inside should not be on when on low beam. Check the wiring at the switch on the floor for any corrosion or melted wires. You could try replacing the switch.
Thanks for replying!

Both switches were replaced with new ones. Nothing changed.

I took a separate good 12 volt battery. Hooked the ground to the ground terminal (right terminal)on the light and the hot to the low beam terminal (left) of the light. It worked normally. I then switched the hot wire to the top terminal which is the high beam and the light shines dim. Both low beam lamps do this. I'm officially stumped.
Old 10-22-2013, 07:05 PM
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wombvette
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Its the ground. They are feeding through the lamp filiments.
Old 10-23-2013, 01:58 PM
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speedybmc
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Alright guys i got it figured out. What it was the low beam and the ground on the plug were swapped. I swapped them around on both sides and its working like a charm now.

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