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I have nearly completed the electric headlight conversion in my 78 ($100 ebay version). I can't seem to find the wire needed to have the headlights pop up ONLY when the headlights are on (not when just the running lights are on.)
Tapping off from one of the headlight wires will not work because the brights run off of a different wire as do the headlights when the brights are on. There has to be a wire coming from the headlight switch that must go to the bright switch.
Any help would be appreciated.
Last edited by vetpace78; May 16, 2026 at 09:18 PM.
Yes there is. You need to run a wire through the firewall and get behind the dash. Intercept the wire from the light switch that goes to the high low switch. Probably easiest to find right at the dimmer switch. Which is mounted to the column on the left hand side just behind the dash. I think you'll need to remove the crossover air-con duct to get at it. Should be a light blue wire that comes from light switch to dimmer switch. Then light green (high beam) and tan (low beam) wires out of dimmer switch.
You need to "T" off of that light blue wire.
Yes there is. You need to run a wire through the firewall and get behind the dash. Intercept the wire from the light switch that goes to the high low switch. Probably easiest to find right at the dimmer switch. Which is mounted to the column on the left hand side just behind the dash. I think you'll need to remove the crossover air-con duct to get at it. Should be a light blue wire that comes from light switch to dimmer switch. Then light green (high beam) and tan (low beam) wires out of dimmer switch.
You need to "T" off of that light blue wire.
I did this but the lights popped up as soon as the running lights came on. Is there a wire that energizes the lights before the bright switch?
The light blue wire is ONLY hot when switch is pulled fully to headlight position. The running lights are powered by the brown wire out of the headlight switch. There is also a light blue wire from the direction switch to the left front marker lights. This would do what you are describing.
Are you absolutely certain you have connected to the light blue wire at the high low switch? Left side of the column.
Just behind the dash. This wire goes only from the ignition switch to the high low switch.
Last edited by 4-vettes; May 16, 2026 at 11:24 PM.
The light blue wire is ONLY hot when switch is pulled fully to headlight position. The running lights are powered by the brown wire out of the headlight switch. There is also a light blue wire from the direction switch to the left front marker lights. This would do what you are describing.
Are you absolutely certain you have connected to the light blue wire at the high low switch? Left side of the column.
Just behind the dash. This wire goes only from the ignition switch to the high low switch.
No I'm not. It's a god awful place to be trying to rewire anything. The wire I used might have been green. I'll try to get a better look in the morning.
Step one. Find the high-low switch. Low on the column, left hand side. Just behind the lower dash pad. There will be a connector on it. 3 wires as I described above.
God awful place? Seriously it's not that hard to access if your a contortionist.
If it were easy everyone would be doing it.
The more expensive and higher quality kits are plug and play.
On a 78 the wire color feeding the dimmer switch is Yellow...
Circuit #10
Here is the drawing for the Park/License/Turn/HazWarning/Stop 1978
The only Green wire from headlight switch is for the Instrument lamps...
The Green wire circuit number is NOT labeled on this drawing but on Page 28 it is...Circuit #44
If OP used the Green wire (Circuit #44) to energize relay(s) the headlight buckets would open in either 1st or 2nd headlight switch position(s)
Last edited by bmotojoe; May 17, 2026 at 06:25 AM.
On a 78 the wire color feeding the dimmer switch is Yellow...
Circuit #10
Here is the drawing for the Park/License/Turn/HazWarning/Stop 1978
The only Green wire from headlight switch is for the Instrument lamps...
The Green wire circuit number is NOT labeled on this drawing but on Page 28 it is...Circuit #44
If OP used the Green wire (Circuit #44) to energize relay(s) the headlight buckets would open in either 1st or 2nd headlight switch position(s)
OMG thank you! The yellow wire! Worked perfectly and was much easier to get at when I realized where the blinker switch was.
Electric headlight conversion (switch wire)
