kept stumbling past the "tech section" i guess, i have a couple questions that i am having trouble finding answers to elsewhere, perhaps if i post here.
'79 240D 123 616

1) rear window defroster. Only one line was heating, and only half of it. I looked, and since one side is all connected along, and same with the left side, that even if i fixed that one horizontal line, all the others still won't work. I noticed on the one, in the dark, i could see a spark occuring right in the middle (it's a hot spot, where it defrosts in a larger area than the lines) then on the other side it doesn't work. I have one of those repair kits, but since it's not a few spots, this looks hopeless. Idea's?

2) the front defroster, actually the center switch goes to "high" then to "def" for added air, i think it must shut off the dash or feet for "def". I noticed naer the accelorator, the line is there, with the curled ends and all. when i twist the switch, it actuates, i just don't know where the connection needs to be made. help?

3) any leads on purchasing R12 cans? I have a shop that can refill my system, probably cost $150, when i was told by previous owner (he has a receipt of full car inspectIon) it says "low". I haven't tested it yet, the switch is behind the bezel. the full bezel (where rear defrost switch is too) has been replaced with a "rocker switch only" bezel, no circle for dial. so i need to pull that out and just test the A/C to see if it will even cycle. my experience is they won't cycle if there is a low charge. I thought about getting a 135 retrofit kit, however i've been told that is not good on the system, it was made for R12 and it is harder on it. ideas?

i sure appreciate it

Guy