When does the rear fog light turn on?
 

I want to install a rear fog light but would rather not run a new wire from the front to the rear. I noticed that there is a spare gray wire coming off the driver's taillight harness. I have confirmed that this is the power source for the parking lights. Is the rear fog light hooked into the parking lights or is it supposed to have a seperate wire that taps into the front fog lights?

Thanks,

It should only come on with the fog lights and normally has a wire that originates at the fog light switch. I don't have the schematic for a '79, but the 81 schematic shows a white/green wire coming from pin II of the fog light switch and going to a connector (6-pin underdash I think) and coming out the other side of the connector as a white/red wire and going directly to the rear fog light. I suspect the color code is the same and if you look, you should have that wire too.

if you have the front fog light switch, then pull it out and turn right. it should click. then run out back and see if you have juice going to the wire. i bet it wont be that easy.

Fintstone, I have copied your comments into what is becoming the ultimate description of the wiring diagram ever attempted outside the design studio. I am beginning to think in shapes of wiring diagrams and it is impacting my love life...

Rich

Amen... effin idiots!:rolleyes: I'm so cool with my rear fog lights on in clear weather.

That said, they are great to have in real fog. They really make a difference.

Rich
As Vash posted, the circuit is designed so that you can either turn on just the front fog lamps by simply pulling out the foglight knob, or turn on both the front and rear foglights by pulling out the knob and clicking it to the right.
I reread your original post and wanted to make sure that you know that the rear fog lamp is mounted on the left...so look in the driver's (left) side tail light harness.
Sorry about your love life.
Stoney

Thanks, I did not know that. That must explain the two extra terminals on the back of the switch which just have a jumper wire covering the two.

Rich

This thing about keeping on the (rear - red) fog lights at any time, over here it is illegal to keep them on when there's no fog, and -if I'm not mistaken- I've read that these lights are in fact harmful to your eyes (when there's no fog). Sue them ijuts!

BTW, them fog lights appear to be "great" when there is fog, but the fact is that, yep, when you clearly see cars' foglights in front of you, you may be tempted to go just that much faster... Bad news for you if there's a pile-up ahead, without shining fog lights.... Every year, there's massive pile-ups in thick fog with dozens of cars involved on the "great" German autobahns with those "great" German drivers (please do NOT think I am knocking German drivers, or Germans -I lived there and I like them, in general)- entire autobahns driving "en bloc" through thick fog at over 60 mph...when even German drivers fail, what to think then of some other ones, perhaps closer to the homeland??? Bright fog lights induce false security!!!