rear defroster help!!!

[Dakota1820]

Ok guys so a couple months ago I reglued my rear Defroster tab back on using the correct glue. Worked great!!! Then tojight I noticed it wasn't working hardly at all it took 20 mins to get the condensation off the window and it did in an angle going across the window from lower driver side up and the last part to clear was the passenger side . thats the side I fixed. I checked it with a multi meter. I was getting .22 on the ac setting. I need to learn how to use a multi meter better. But I'm confused it is getting power because when I touched the passenger side tab it would spark a little. So why is it not working well? And can anyone tell me how to check it correctly. Also the lines across the window are in good shape. Thanks guys. Your always a big help !.

 

[The_Jeff]

Your multimeter should not be drawing enough power for a spark. I suspect that passenger side tab has a poor connection, and your simple act of touching it is mechanically jarring it, making the spark.

 

[JHZR2]

Not sure what youre trying to sense. It should be DC. Connetion between the wire that attaches to the defroster grid and a ground point on the body should give you 12-14v with the meter set to VDC. Putting the meter on A setting, and the leads between the feeder wire and the grid, you should see some current flow.

If there are two leads (a + and a ground) on the grid, setting the meter to ohms should allow you to determine the resistance of the grid. If it is infinite, then the grid is broken.

 

[andyd]

on my BMW , when the tab fell off the window grid, I made up a 10 awg pig tail with a female on one end to plug into the harness and a big ring terminal which I put on the contact patch and held it in place by jamming it under the rubber gasket. Works fine.

 

[Dakota1820]

If I rub a piece of wire around where the tab connects it sparks to. How much power should the Defroster put out

 

[mechtech2]

Like mentioned , use the DC setting.
You may have another rear defroster problem besides the actual contact. Grid lines can be interrupted also.

 

[Dakota1820]

I will check it and report back.

 

[Dakota1820]

So here's the update. Everything reads right around 14.25v except the wire on the passenger side. The wire leading to the tab shows .5 volts the tab shows .5v but the grid around it and even where the tab hooks to shows 14.25 to 14.32 what does that mean? Does power come from both sides or does it come in one and out the other side?