[69hardtop]

Well, I’ve searched the forum and you would think I should have this figured out by now....but I haven’t. 64 GTO hardtop - dome light works, both door switches turn the dome lamp on or off and with the doors closed the light switch will turn on dome lamp when rotated fully counter clockwise. So, I think all my basic wiring in place is correct (I do have all new M&H harnesses installed on the car and everything works fine).
I want to hook up the single courtesy light that installs directly over my console, it has an orange lead and a white lead. Following my wiring laminated guide, orange should go to fuse block tab under “Courtesy light” which is 12V hot all the time, and white should go to the open white connector under the dash that appears to be wired to both the door switches and headlamp switch.
Here is my question/dilemma/brain fog: when the doors are open, my dome lamp lights as it should, and the white wire connector under the dash has no power so I assume it would ground out the courtesy light and it would illuminate the courtesy lamp along with the dome lamp. Is this correct ? The reason is that when I close the door the dome lamp goes out as it should, but that same white connector that I thought grounded out the circuit now is hot with 12V ....I can’t have 12V on the orange and 12V on the white, right ?
Any thoughts on what I may have done wrong.....I haven’t snapped in the courtesy harness as I’m worried I’ll damage something, only have been probing with test light and voltmeter.
Pics attached of my courtesy light and the open white connector
Thx in advance

["QUICK-SILVER"]

Dome and courtesy work by grounding.

White will show hot, untill its grounded.

You've got this
Clay

[OG68]

When the door is closed the orange 12 volt power feeds through the light bulb and to the white ground wire. Since the ground is open (door closed) you will read just slightly less than the orange wire voltage on the white. This is because the bulb is a load and drops the voltage when read by a meter.. Once the door opens the white wire becomes grounded and will read zero.

[69hardtop]

Originally Posted by OG68

When the door is closed the orange 12 volt power feeds through the light bulb and to the white ground wire. Since the ground is open (door closed) you will read just slightly less than the orange wire voltage on the white. This is because the bulb is a load and drops the voltage when read by a meter.. Once the door opens the white wire becomes grounded and will read zero.

Thx
Ill try this by using a test bulb i have with clips to see if it loads the circuit

I’m just pretty wary as this 12V always powered connector at the fuse box is not fuse protected, don’t want to plug in this harness and burn up some wires, or the car, garage, house etc

["QUICK-SILVER"]

Originally Posted by 69hardtop

Thx
Ill try this by using a test bulb i have with clips to see if it loads the circuit

I’m just pretty wary as this 12V always powered connector at the fuse box is not fuse protected, don’t want to plug in this harness and burn up some wires, or the car, garage, house etc

Power to that terminal comes from the same hot wires that power ignition switch and headlight switch. A single courtesy light bulb wont add enough amp draw to count, when compared to what's already going on.

Those main un-fused (don't go through a fuse in the fuse box) wires are protected by fusible-link wire under the hood. Fusible-link is 4 wire gauges smaller than the wire it supplies power to.

You're using factory terminals and connectors made to do exactly what you're doing.

Test for fun but not a problem
Clay

[69hardtop]

Originally Posted by "QUICK-SILVER"

Power to that terminal comes from the same hot wires that power ignition switch and headlight switch. A single courtesy light bulb wont add enough amp draw to count, when compared to what's already going on.

Those main un-fused (don't go through a fuse in the fuse box) wires are protected by fusible-link wire under the hood. Fusible-link is 4 wire gauges smaller than the wire it supplies power to.

You're using factory terminals and connectors made to do exactly what you're doing.

Test for fun but not a problem
Clay

Thx so much Clay, I’ll give it a try

[69hardtop]

Originally Posted by "QUICK-SILVER"

Power to that terminal comes from the same hot wires that power ignition switch and headlight switch. A single courtesy light bulb wont add enough amp draw to count, when compared to what's already going on.

Those main un-fused (don't go through a fuse in the fuse box) wires are protected by fusible-link wire under the hood. Fusible-link is 4 wire gauges smaller than the wire it supplies power to.

You're using factory terminals and connectors made to do exactly what you're doing.

Test for fun but not a problem
Clay

Plugged in today, works perfect....not sure why I didn’t get the hot-to-ground change.
Thx for the help