What is a "Light Minder"?
 

I have a brown wire coming out of my headlight switch wiring plug that is connected to nothing. The wiring diagram in the 1970 Pontiac Service Manual labels it "Light Minder" but doesn't show what it connects to, and doesn't say what a light minder is. On another site, it was suggested maybe a chime if you leave the lights on. Ideas? My car has the Headlight Delay option, but nowhere to plug it into that.

It is a buzzer that let you know if you left your lights on.

Whatever it was, it was optional as expressed by the dashed wire on the schematic. Do you have the accessories listings for '70? The only thing in the listings I can find is "Rear light monitoring system" but that wasn't listed for '69 or '71, so it appears to be a 1 year only thing and I do not have access to the full '70 service manual electrical to see if it's listed there. I presume it'd be like the higher end Buicks and Cadillacs that had indicators to let you know if a rear tail light was out, but I've never seen one on a Pontiac before.

The headlight delay ('70 only as well) I'm sure had it's own box to control everything and could have been taken off of this point as well, although this wire activates when the parking lights are turned on, not just the headlights.

Makes good sense, but I just don't see it listed on the schematics for the car. All of my cars are blurring in my mind, but I know my '71 Bonneville has the key buzzer working perfectly but it does not have a headlight buzzer nor do the manuals and drawings list one. '69-70 was a weird time for options before they consolidated all of the body chassis B-body lineup in 1971.

I looked at the 1970 accessories brochure. Page 21 shows an instrument panel warning light option that includes a 'headlight on' warning light. http://oldcarbrochures.org/United%20...sories-21.html

There's also a taillight monitoring system option as well as the headlight delay option on page 24 (the taillight monitoring system uses fiber optic cables so it wouldn't be that anyway.) http://oldcarbrochures.org/United%20...sories-24.html

If you look at the previous page (12-64), the brown wires go to the running lights so as a head/parking light warning it would make sense. OTOH some paces street parking requires leaving the "parking" lights on so a buzzer/chime tied to the ignition would not be a good idea.