Author Topic: High Beams not Working!  (Read 10905 times)

Offline MyOldScottsdale23

  • Newbie
  • Posts: 48
  • Newbie
High Beams not Working!
« on: February 08, 2012, 11:30:48 AM »
I just bought a '85 SierraClassic 4x4 and only one low beam headlight was working. I replaced all 4. Now both low beam or upper lights work but I get no lights when I swith on the high beams. The indicator blue lights come on the dash but no headlights. Any help or suggestions would be greatly appreciated. Thanks in advance!

Offline winky

  • Junior Member
  • ***
  • Posts: 509
Re: High Beams not Working!
« Reply #1 on: February 08, 2012, 11:33:32 AM »
my 77 started doing the exact same thing.. i replaced my dimmer switch and light switch. not sure what the solution is, haven't really looked into it much but i would also like to know the solution.

Offline bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 5636
Re: High Beams not Working!
« Reply #2 on: February 08, 2012, 05:16:45 PM »
Check your headlamp grounds.  Do the headlamps go dark on highbeam?
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline MyOldScottsdale23

  • Newbie
  • Posts: 48
  • Newbie
Re: High Beams not Working!
« Reply #3 on: February 08, 2012, 09:59:28 PM »
Yes when it goes to switch to the bottom two (high) beams the top two (low) beams go off

Offline bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 5636
Re: High Beams not Working!
« Reply #4 on: February 08, 2012, 10:44:09 PM »
So neither the uppers nor lowers light with highbeam.  Sounds like it might be a dimmer switch or connections at the dimmer.  Unplug a headlamp and check for power (cause it's easy to get to).  As I recall, black is ground, tan is low, and green is high.  If green is dead, check the dimmer.  If green and tan aren't dead, check the ground.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline bake74

  • Senior Member
  • ****
  • Posts: 5871
    • Build Thread
Re: High Beams not Working!
« Reply #5 on: February 09, 2012, 06:39:49 AM »
So neither the uppers nor lowers light with highbeam.  Sounds like it might be a dimmer switch or connections at the dimmer.  Unplug a headlamp and check for power (cause it's easy to get to).  As I recall, black is ground, tan is low, and green is high.  If green is dead, check the dimmer.  If green and tan aren't dead, check the ground.

     Sounds like it is definitely a problem with a connection, bd is right, start at the lights themselves and check for power, then work your way back to switch and dimmer, this will be the best way to pin point the problem without throwing parts at it.
      Keep us informed of what you find.
#1: The easiest and most obvious solution to any problem is 99% of the time correct.
#2: There is no such thing as impossible, it just takes longer.
  74 k10, 77k10    Tom

Offline MyOldScottsdale23

  • Newbie
  • Posts: 48
  • Newbie
Re: High Beams not Working!
« Reply #6 on: February 09, 2012, 10:25:49 PM »
So I have noticed that dash lights have been flickering and I have to adjust the dimmer, but the low beams work fine. So I'm confused as to why it would affect the high beams when they work off the wiper/cruise switch on the column.

Offline bake74

  • Senior Member
  • ****
  • Posts: 5871
    • Build Thread
Re: High Beams not Working!
« Reply #7 on: February 10, 2012, 12:27:03 AM »
So I have noticed that dash lights have been flickering and I have to adjust the dimmer, but the low beams work fine. So I'm confused as to why it would affect the high beams when they work off the wiper/cruise switch on the column.

     Mine is a 74, but when I first got it, it had a similar problem.  I found I had some faulty grounds and as soon as I fixed the grounds the flicker in my dash lights went away.
#1: The easiest and most obvious solution to any problem is 99% of the time correct.
#2: There is no such thing as impossible, it just takes longer.
  74 k10, 77k10    Tom

Offline bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 5636
Re: High Beams not Working!
« Reply #8 on: February 10, 2012, 09:02:56 AM »
So I have noticed that dash lights have been flickering and I have to adjust the dimmer, but the low beams work fine. So I'm confused as to why it would affect the high beams when they work off the wiper/cruise switch on the column.

Headlights and dash lights are separate circuits.  Don't confuse the two.  Diagnose them independently.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline joel

  • Newbie
  • Posts: 49
  • Newbie
Re: High Beams not Working!
« Reply #9 on: February 10, 2012, 09:46:17 AM »
I had the same thing basically with my 86 .  Make sure the connectors at the lights look good not broken or melted .  If you do have to have new switches, I recommend using Delco replacements, the cheaper ones i bought first were not as good and the cheap headlight switch i bought had a faulty circuit breaker inside it (non-servicable). You have good advice in checking all grounds and connections. Good luck and keep after it!
tailgate fisherman

Offline winky

  • Junior Member
  • ***
  • Posts: 509
Re: High Beams not Working!
« Reply #10 on: February 10, 2012, 09:55:33 AM »
I had the same thing basically with my 86 .  Make sure the connectors at the lights look good not broken or melted .  If you do have to have new switches, I recommend using Delco replacements, the cheaper ones i bought first were not as good and the cheap headlight switch i bought had a faulty circuit breaker inside it (non-servicable). You have good advice in checking all grounds and connections. Good luck and keep after it!

here at the chevy dealership all we use is delco parts, its what gm mostly uses now. couldn't agree more, hope you get your problem fixed.