Testing Rear Window Defroster ?

[cary]

Putting the car in the trailer tonight. To deliver to the painter tomorrow. Finally read to go.
I have learned a lot about my car.

Question : When I pull out the rear glass. Can I test the grid for continuity ? If so how ? Not wired after the PO painted it last time.

If it has cracks in the grid, how do I go about tracking them down ? Where to put the leads ?

TIA .........

[david914]

Cary,

Your defroster grid has two "buss bars", for lack of a better term, that run along the sides of the rear glass. One side is grounded, and the other is fed 12 volts through a current limiting resistor network and relay in the engine compartment. Basically, the best thing to do is get everything hooked up, wait 'til a damp/dewy morning and turn it on. Watch to see what areas (if any) don't defrost/defog and mark them with a grease pencil. I understand that you can purchase a grid repair kit from an auto parts store or dealer. Find the break (it shouldn't be hard to see) and repair it using the kit. Should be pretty easy to do.

[steve rush]

I take a test lite and work my way across glass and mark with felt tip where I lost power. Buy Bituminous (sp ck) paint (with iron in it ) and touch up usually over scratch or thin spots...let dry and retest.....repeat....for longer spots I use thin plastic cards taped to glass to allow a thin paint line. The only hard part is finding so comfortable position to paint upside down in the rear sundeck of my car (read 6 feet 200 lbs in a 10" by 3 foot spot)....usually requires a 2 to 1 ratio of hot tub time to paint time to repair my neck.

[Roland Kunz]

Hello

Yes you can test the grids with a Ohmmeter. They are around 50 Ohm.

You can run the tip from the ohmmeter probe along the grid lines to find dead spots.

Grüsse

[sayah]

One the same subject but different job. Does anyone know if it is possible to connect the wires to the glass plug without removing the glass?