Headlight switch issues
Thread Starter
Intermediate
Joined: Oct 2016
Posts: 31
Likes: 0
Headlight switch issues
While I suspect replacing the HL control in my 79 will solve these issues:
1. Headlights on and rotation of dimmer causes drastic tach variations.
2. Headlights on causes issues with instrument lights.
3. Headlights on causes reverse function of high beam/low beams.
4. Headlights on causes turn signal indicators to "stick" on given dimmer rotation position.
Everything works fine when HLs are off. Day car only? LOL! My wife and I occasionally like to enjoy an evening dinner date in the ole Vette.
Thanks all!
1. Headlights on and rotation of dimmer causes drastic tach variations.
2. Headlights on causes issues with instrument lights.
3. Headlights on causes reverse function of high beam/low beams.
4. Headlights on causes turn signal indicators to "stick" on given dimmer rotation position.
Everything works fine when HLs are off. Day car only? LOL! My wife and I occasionally like to enjoy an evening dinner date in the ole Vette.
Thanks all!
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,112
From: Crossville TN
The grounding in question is likely in one of two (or in both) places:
1. The main headlamp ground wire/terminal on the framework behind the headlamp buckets (left of center)
2. Omitted, damaged, or poor contact on the headlamp switch grounding strip (metal strip mounting under the switch mount and running to ground point on inside of driver's dash pad).
Check images/drawings in the electrical section of your A.I.M. for detail.
If you correct the grounding problems and the headlamps still work "backwards", the wiring on the headlamp 'brights' switch (floor mounted) is not connected correctly....OR... the sockets on the HI and LO beam lamps are reversed. Again, check AIM for correct orientation.
1. The main headlamp ground wire/terminal on the framework behind the headlamp buckets (left of center)
2. Omitted, damaged, or poor contact on the headlamp switch grounding strip (metal strip mounting under the switch mount and running to ground point on inside of driver's dash pad).
Check images/drawings in the electrical section of your A.I.M. for detail.
If you correct the grounding problems and the headlamps still work "backwards", the wiring on the headlamp 'brights' switch (floor mounted) is not connected correctly....OR... the sockets on the HI and LO beam lamps are reversed. Again, check AIM for correct orientation.
Last edited by 7T1vette; Jun 14, 2020 at 02:41 PM.
Pro
Joined: Nov 2016
Posts: 729
Likes: 118
From: Kelowna British Columbia
I would get a wire from negative battery and touch it to the ground on headlight switch or ground at lights to test. Battery ground is where grounds all end up . Getting at back of headlight switch is no easy task but if you read up it is doable without taking dash out. These headlight switches are terrible and even new ones are hit and miss. Probably where your trouble is
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Thread Starter
Intermediate
Joined: Oct 2016
Posts: 31
Likes: 0
The grounding in question is likely in one of two (or in both) places:
1. The main headlamp ground wire/terminal on the framework behind the headlamp buckets (left of center)
2. Omitted, damaged, or poor contact on the headlamp switch grounding strip (metal strip mounting under the switch mount and running to ground point on inside of driver's dash pad).
Check images/drawings in the electrical section of your A.I.M. for detail.
If you correct the grounding problems and the headlamps still work "backwards", the wiring on the headlamp 'brights' switch (floor mounted) is not connected correctly....OR... the sockets on the HI and LO beam lamps are reversed. Again, check AIM for correct orientation.
1. The main headlamp ground wire/terminal on the framework behind the headlamp buckets (left of center)
2. Omitted, damaged, or poor contact on the headlamp switch grounding strip (metal strip mounting under the switch mount and running to ground point on inside of driver's dash pad).
Check images/drawings in the electrical section of your A.I.M. for detail.
If you correct the grounding problems and the headlamps still work "backwards", the wiring on the headlamp 'brights' switch (floor mounted) is not connected correctly....OR... the sockets on the HI and LO beam lamps are reversed. Again, check AIM for correct orientation.