Low Beam Light Goes Out When High Beams Turned On

[KSSB]

Edit: Solved. Was an obvious solution I should've thought to check.

I have an 85 C10 Silverado, with quad headlights. The high beams get switched on by pulling the turn signal switch. Both low beams work when the switch is on low beams, but when I switch to high beams, the driver's side low beam goes out. When I switch back to low beams, the driver's side low beam light comes back on.

Edit: Both low beam lights and high beam lights are brand new.

Any idea what could cause that? Or, does anyone have an idea where to start looking to get this fixed?

Thanks for any help, or guidance anyone can provide.

 

[edgephoto]

Bad bulb?

 

[rlhow]

the bright beam bulbs have (1) 55 watt filament, the low beam bulbs each have 2 filaments (1) 35 watt for low beam and (1) 55 watt for high beam. As stated above, you probably have a bad bulb... burnt 55 watt filament. When you switch to bright the 35 watt filaments are deenergized and all (4) bulb's 55 watt filaments are energized

 

[TotalyHucked]

Sounds like you just need a new bulb in that location. Before doing that though, I'd do the wiggle test. Turn the highs on and wiggle the connector to see if the bulb lights up, could just be a loose connector. That happens every once in a while in my truck, I just re-position the plug a bit and I'm good for another year+

 

[KSSB]

Bad bulb?

I left that out of the my original post and edited it to add that all 4 bulbs are new.

 

[KSSB]

the bright beam bulbs have (1) 55 watt filament, the low beam bulbs each have 2 filaments (1) 35 watt for low beam and (1) 55 watt for high beam. As stated above, you probably have a bad bulb... burnt 55 watt filament. When you switch to bright the 35 watt filaments are deenergized and all (4) bulb's 55 watt filaments are energized

Thank you for explaining how they operate. I forgot to mention in the OP that all 4 bulbs are new.

 

[KSSB]

Sounds like you just need a new bulb in that location. Before doing that though, I'd do the wiggle test. Turn the highs on and wiggle the connector to see if the bulb lights up, could just be a loose connector. That happens every once in a while in my truck, I just re-position the plug a bit and I'm good for another year+

I'll check the connection today, I forgot to mention and I edited my OP that all 4 bulbs are new.

 

[TotalyHucked]

I'll check the connection today, I forgot to mention and I edited my OP that all 4 bulbs are new.

If that doesn't do it, then I'd swap that bulb with the other low beam and see if the problem follows. If it does, the bulb is bad even though it's new

 

[KSSB]

If that doesn't do it, then I'd swap that bulb with the other low beam and see if the problem follows. If it does, the bulb is bad even though it's new

Ya know, sometimes, (more than I care to admit, honestly), I overlook the simplest test. Lol

I'll definitely try that today and see if it follows.

Thank you!

 

[KSSB]

So, it turned out to be a bad headlight, even though it is brand new. It went out on the passenger side, when the high beams were turned on.

Thank you all for holding my hand. Lol I really should've thought of that.

I'm colorblind, so I've always shy'd away from electrical issues, but I need to get my head in the mindset of realizing I may not always need to chase wires and try to follow the colors of those wires.

Thanks again, everyone. I sincerely appreciate it!

 

[Sad Sack]

So, it turned out to be a bad headlight, even though it is brand new. It went out on the passenger side, when the high beams were turned on.

Thank you all for holding my hand. Lol I really should've thought of that.

I'm colorblind, so I've always shy'd away from electrical issues, but I need to get my head in the mindset of realizing I may not always need to chase wires and try to follow the colors of those wires.

Thanks again, everyone. I sincerely appreciate it!

Let's hear cheers for TotallyHucked!

 

[KSSB]

Let's hear cheers for TotallyHucked!

Totally!! (Pun intended) @TotalyHucked defnitely gets the "check the obvious, fella" award.

 

[TotalyHucked]

Haha glad it was that simple! I've been burned plenty of times over thinking and going way too deep when it's something super simple on the surface. My dad has laughed at my suffering MANY a time and I've finally learned to slow down, step back and try the simple stuff first

 

[idahovette]

Haha glad it was that simple! I've been burned plenty of times over thinking and going way too deep when it's something super simple on the surface. My dad has laughed at my suffering MANY a time and I've finally learned to slow down, step back and try the simple stuff first

That's Dads' prerogative........laughing at their kids mistakes..........dumb a$$

 

[goldpack]

So, it turned out to be a bad headlight, even though it is brand new. It went out on the passenger side, when the high beams were turned on.

Thank you all for holding my hand. Lol I really should've thought of that.

I'm colorblind, so I've always shy'd away from electrical issues, but I need to get my head in the mindset of realizing I may not always need to chase wires and try to follow the colors of those wires.

Thanks again, everyone. I sincerely appreciate it!

if you need to revisit the problem like a repeat or another headlight snafu.

they do sell these at LMC truck for about $35.00
Heavy-Duty Headlight Harness
Part #: 36-3581

it has new wires and relays in it, so it takes the guess work / head scratching out of what is a 40 year old antique problem.....'

edit: and other members recommended it for my truck's similar problems. ...along with a dimmer switch. (after I bought new sealed beams, which did not want to always work properly).