71 Impala headlight problems

headlights

#1

I have a 71 Impala, the problem I’m having is with the headlights. I can not get the lights to work with the head light switch. I pull the switch on and get the running lights and dash lights but no headlights. I have changed the headlight switch and still same problem. When I purchased the car we rigged it so the lights would come on by connecting directly to the battery (thats getting old) so I’m assuming nothing is wrong with the actual lamps themselves. Another thing is there is a loud bussing sound whenever I open the drivers side door, kind of like a reminder that you would hear when you leave your headlights on. What should I look for next?? Any help will be greatly appreciated, Thanks


#2

Check that you have power into and out of the dimmer switch.

Power into the switch is the light blue wire. Power out Tan for high beam and light green for dipped headlights.

I see you changed the switch, but did you check for power. The headlight feed is into the light switch is the red wire - this is fed by an inline fusible link, it may have blown.


#3

With the headlight switch ON, check for power at the beam selector switch. The light blue wire should have power. If there is power at the light blue wire then there should be power at either the light green? or tan? wire depending on whether high or low beam is selected.
If you have power at the lt. green or tan wire wire then you should check the ground wire for the headlight bulbs. Due to the car’s age it’s possible the ground connection could be corroded at its mounting screw.

(I’m knocking on wood here this old wiring schematic is accurate as to color codes.)


#4

Your wiring’s correct ok4450, I got one here. But the poster says his headlights work with a hotwire to the battery, therefore I think your right, it’s either the beam selector switch or more likely the fusible link feed to the light switch is blown.


#5

I finally had time to try your suggestions. I do have power, inline fuse is okay. I changed out the beam selector switch and I do have power there also. Now I have high beam but no low beam. When I check for power to the low beam headlights I have no juice at the plug that connects to the headlight. I still have a loud buzzing noise when I open the drivers side door. Any suggestions??


#6

I finally had time to try your suggestions. I do have power, inline fuse is okay. I changed out the beam selector switch and I do have power there also. Now I have high beam but no low beam. When I check for power to the low beam headlights I have no juice at the plug that connects to the headlight. I still have a loud buzzing noise when I open the drivers side door. Any suggestions?? Would the ground wire cause the low beans not to work but high beams would work fine??


#7

The high beam switch should also switch power to the low beams when the highs aren’t selected. It sounds like there is a break in the wire between the switch and the low beams. Do you see the same colored wire at the low beams and the switch?


#8

Check for a faulty headlight relay.

Tester


#9

No relay shown in the circuit Tester.

Provided the dimmer switch is getting power at both the high beam (lt green) and the low beam (tan) wires at the dimmer switch, it’s either a broken wire or a bad inline connector somewhere ~ though the circuit doesn’t show any inlines either.

Continuity test the lines next methinks…

This could be as simple as bad connector at the dimmer switch.