Headlights on bright, bottom only

[plckidd]

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Hey y’all. I noticed today that my low beam lights work fine, but when I switch to high beams only the bottom lights come on. The top low beams go out. Is this normal or should all 4 be lit using brights?

 

[Turbo4whl]

Yes, all four lights should be on for high beams. Upper lamps should have 3 prongs, inside 2 filaments.

So either wrong bulbs, or wiring issue, or both upper lamps have one filament out.

 

[plckidd]

Yes, all four lights should be on for high beams. Upper lamps should have 3 prongs, inside 2 filaments.

So either wrong bulbs, or wiring issue, or both upper lamps have one filament out.

Thanks! Yes, there are 3 prongs going to the top lights and 2 prongs going to the bottom lights. I just replaced all 4 headlights to the newer style, but the old lights did the same. I would think it is in the wiring. hmmm now the fun begins!!

 

[gmbellew]

that is how the 89-91 headlights work. maybe somebody used the wrong harness if the wiring isn't factory?

 

[plckidd]

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It looks like the top lights are staying on, but seem to dim when brights are on. Is this normal?

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[PrairieDrifter]

Nope not normal. I switched my lamps locations because of my lift, I have the lower two as low beams and upper two as high beams.

This is high beams with low battery voltage and not aimed or even mounted in this picture.

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[PrairieDrifter]

I'd be suspicious of a headlight switch, you seem to have resistance somewhere. Would also recommend doing a headlight relay kit, takes the strain off the headlight switch to keep from melting it. Chances are your switch is melted, I've had 4 trucks with these switches melted.

 

[plckidd]

Well I figured it out. Ended up swapping the hot and ground wires on the low beam harness. Problem solved. Here is a pic with low beams only and a pic with high beams on. Thanks for all your help!

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[Goldie Driver]

Well I figured it out. Ended up swapping the hot and ground wires on the low beam harness. Problem solved. Here is a pic with low beams only and a pic with high beams on. Thanks for all your help!

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Nice ! How did you figure it out?

 

[plckidd]

Nice ! How did you figure it out?

Honestly... it was pure luck! I pulled all wires from plastic housing on the drivers side to squeeze connectors for a tighter fit on the bulb. The passengers side was just disconnected. When I connected them to the light on the drivers side, I turned the lights on and it looked great. When I went to the passenger side to do the same thing, I noticed the wires were not the same as I did on the drivers side. I swapped those and made tighter connections and all is well. I’m glad this was the case.... vehicle wiring sucks!

 

[Grit dog]

Good you get er figured out!
Now maybe a little more about the truck and that nice looking TA there next to it. Both are sharp looking vehicles!

 

[Goldie Driver]

Good you get er figured out!
Now maybe a little more about the truck and that nice looking TA there next to it. Both are sharp looking vehicles!

Dammit - I missed that !!

 

[plckidd]

Good you get er figured out!
Now maybe a little more about the truck and that nice looking TA there next to it. Both are sharp looking vehicles!

Thanks man! It's always easy once you find the problem!! LOL.

I'll post a few more pics of my truck soon...

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It is getting new suspension, wheels, dash, gauges, touchscreen radio and a custom ash tray delete for phone cradle/USB connection and some new engine components. Trying to talk myself out of EFI convert. ??

The 77 TA has been a 12 year project. I have a 383 SBC going in next month. Just need a few more engine dressings! I had the car basically, frame off restored. It is a Hurst edition with the T-tops and 4 speed Borg Warner tranny. It should be on the road this year!

 

[Goldie Driver]

Thanks man! It's always easy once you find the problem!! LOL.

I'll post a few more pics of my truck soon...

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It is getting new suspension, wheels, dash, gauges, touchscreen radio and a custom ash tray delete for phone cradle/USB connection and some new engine components. Trying to talk myself out of EFI convert. ??

The 77 TA has been a 12 year project. I have a 383 SBC going in next month. Just need a few more engine dressings! I had the car basically, frame off restored. It is a Hurst edition with the T-tops and 4 speed Borg Warner tranny. It should be on the road this year!

Will the shaker still work with the 383 ?

I think the 80's & 81's came with 305's when there was a 4 speed so it just might ...

 

[Shorty81]

I really like the rallies