No rear window defoger/demister

[g rad]

I've had this 76 911s for five years and have never been able to get the rear defoger to work. I have over 12 v on all 3 contacts on left side, have ground on the right side.... My digital voltmeter has a buzzer for continuity, I get nothing across the painted lines, for continuity.. end to end or inch to inch across individual lines... This is the first time I've been around demister resistance paint, if that is what it is... seems very delicate this paint on glass and can I fix it ?? any help would be appreciated..... plenty of foul weather in Joliet, Il... thanks, Hayseed

[HarryD]

You can fix it with the kit you get from Permatex.



Me and my boy did this last weekend.

To locate the break:

1-Set your voltmeter to volts;
2-Ground the negative lead.

For EACH Wire,

1-Start at the 12 v end (probably the driver side).
2-Touch the positive lead of the meter to the wire. If it is ok, you will see voltage that will go down as you move to the other end of the wire.
3-When you find the voltage suddenly drops to ZERO before you are at the other end, that is your break.
4-Apply paint per instructions and test again.

A few notes:

The paint needs to cure for 24 hours so find the break in each wire and and mark them (I used a grease pencil) on the outside to mark the locations. When they are all marked, go back and apply paint.

Some wires will have more than one break, you may do do this several times to fix them all.

The brush supplied in the kit paints a very FAT line, if I did it again, I would go to an art supply store and get the smallest paint brush they sell.

It is tedious.