Backwards Headlight Wiring?

[bartman]

On my 73 240Z my headlights seem to work properly with the stock wiring, but it seems backwards.  When the lights are turned on the black wire gets power while red/black is ground when using low beams and red/white is ground when using high beams.  This causes problems when trying to upgrade my lights to use relays.  

This can't be correct can it?  And if so, what could be causing this?

 

[zKars]

You're lights are wired correctly. This is the way they come from the factory. The high/low switch decides which side gets grounded (RW or RB) while the common bulb terminal is fed constant +12 via two fuses. 

The Dave Irwin relay upgrade harness reverses this situation without issue in a most elegant manner. All is fine, carry on with your day.

Edited February 4, 2017 by zKars

[bartman]

Thanks.  I looked through a lot of threads and didn't see this information anywhere.

[SteveJ]

It's actually been explained many times:

And it's documented completely in the FSM in the BE section with the wiring diagram.

[bartman]

I stand corrected.  I think the main thing throwing me off on my car is the right headlight power feed is black not red.  I generally don't expect to see power coming from a black wire.

[siteunseen]

That'll change if you ever do any house wiring.

 

[SteveJ]

17 hours ago, bartman said:

I stand corrected.  I think the main thing throwing me off on my car is the right headlight power feed is black not red.  I generally don't expect to see power coming from a black wire.

Clarify what you mean. Where exactly is the black wire? There is a White/Red wire in the dash harness taking 12 VDC+ to the combo switch. The headlights contact in the combo switch will connect to a Red wire in the dash harness that goes to the fuse box. The black wire in the dash harness is the ground for the headlight switch and the horn.

[bartman]

I'm talking about the wires at the headlight bulb connection.

[SteveJ]

It's been 15+ years since I worried about the wires on the connector. The wire colors in the dash harness, body harness and engine harness are what you need to concern yourself with for colors. Those are the ones listed in the FSM.