Lights on but no one is home. . Rear defroster.

[tripplec]

Checked mine and found the ground side lug very loose. Could not really tighten and it popped off a weird stud. Power across the grid. Its quite windy and feeling it warming up wasn't confirmed as happening. I pushed the fiction lug over the stud and its tight enough to conduct the current. Only thing no yet check is grid continuity but seems unlikely the rear window grid is totally open.

Weird setup, work in progress a little later.

 

[tripplec]

Its +4C and it is not getting warm enough to feel. I am not sure is the windshield is heating. I know there is over 14VDC across it from my meter.

 

[Rcflyer330]

Are you testing from the stud or from the actual grid? It is possible the actual stud has broken connection from the grid If you are testing from the connection point to connection point. You need to test from the grid to the grid. It is very possible that all the lines are broken all it takes is the lightest scratch to break them. The grid does not get that hot if it did get hot enough to feel it would probally shatter the glass as soon as you turn it on.

 

[tripplec]

From the stud and lug both ways. Voltage is there at the window but not warming. I'd have to disconnect one side to Ohm the grid and refraining from that at this time. The post/stud is the part secured to the window and appear normal. Originally the negative was floating loose so I felt securing it tight would have been the fix. LOL Not so lucky. Its going to be below freezing tomorrow and I'll see what can be determined. Its not rocket science but the current should be flow. Odds of all parallel grid wire open are infinite IMO. Dahhh

Thanks for your post RCFLYER330

 

[Rcflyer330]

I dont know what type of meter you have or the dc amp rating but i just tested mine with a non contact meter and it read just over 16 amps for a working grid. If your meter is rated 20 amps or more you can remove one power lead from the grid and attact one lead of the meter to the power wire and touch the other meter lead to the grid to measure the power draw. Working grid is approx 16 amps anything under that and grid lines are broken.

 

[tripplec]

Hmm, I have various meters. I was using an old analogue meter on 15VDC range and it swung over. Almost to 15V so the fraction is irrelevant. i have digital meter with DC Amp range 10A max Nothing higher though. I'll do some testing. Its my son's SUV and looking for assistance.

 

[tripplec]

Ok, to confirm the results.
I metered from the grd stud to the +ve, then the window etching bus for the Positve power. OK
-ve etching to +ve also good >14VDC

With engine off no power on window I ohmed across the heating array. +ve to -ve etchings and got very low resistance so the heating etching is good and load is there. Current draw isn't relevant since its not open circuit and power is there at the window circuits of the glass. This elimates the stud to window etching connection being broken, open etc. No weather appropriate to test visually yet.

I did the metering test more than once and the main etching buss providing the -ve as well as the +ve one are easy to make contact with. I am confident its working.

 

[Rcflyer330]

For visually checking you could try a light mist of water with the deforster on after a minute or two you should see the outline of the grid starting to appear.

 

[tripplec]

My son has gone back home. He'll have to do that testing. I did all the work to this end on it and with sound connection it should be working. No reason for it not to be working that I can see. For others wondering. The drivers side is -ve and other is +ve. Both etching sides are easily accessible to probe with a meter to verify power across the heating array. Trouble shooting connection and power issues are easy once you know this.