Low Beam vs High Beam

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82BBC20

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My 82 C20 has the dual stacked headlamps, when lamps are on the low beams come on up top then hit the dimmer switch (floor button) & it switches the lower lamps on but the upper lamps go out. I thought all 4 should be on when brights are on, Anybody know for sure?
 

Goldie Driver

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Smarter people than I say that all 4 should be on.


The searches I did make it appear that the upper lights should have 3cprong bulbs for both high and low beams.
 

bucket

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Yeah, with standard type sealed beam lights, GM wired all 4 to be on when the brights are on.

It may be as simple as two headlights that need replaced.
 

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They all come on just not together, aren’t all the bulbs the same as in single filament?
 

bucket

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They all come on just not together, aren’t all the bulbs the same as in single filament?

The upper lights are low beam AND high beam style. There are two different filaments that light up and they have plugs with 3 terminals. The lower lights are just high beams and only have two terminals.
 

82BBC20

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Got it, Sounds like I need to buy a couple of bulbs now. Thanks for the help!
 

bucket

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It could be a wiring issue, but yeah, bulbs are likely.
 

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Stock is 2 on low and all 4 on high.

I swapped to these a few years back and absolutely love them. Very bright, long range, and a very distinct cut off line on low.

Z-OFFROAD 4pcs 60W Rectangular... https://www.amazon.com/dp/B07ZH7WC53/
 

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