Rear windscreen heater test

[hal7600]

Thus may sound a little basic, but any advice to test whether the rear windscreen heater works? Should a basic continuity test suffice? If the result is no continuity, can it be fixed?

Needless to say the screen is removed from the boot lid

 

[pepper]

The continuity test will only show a problem if the electrics are totally knackered, if one or two line are damaged, as is normally the case then it can be difficult to test. you'll need to be able to check each line individually and I'm not sure if that's possible?

 

[alewis]

I tried it a while back.
If you measure the resistance from the end of each line to the middle of each line you can get a good feel for which lines are good and which are bad (be careful not to damage the line!) (I gave up as once I was looking that carefully I realised they were all damaged)

 

[iMacThere4iAm]

I suppose you could spray water on it and connect a 12V battery to it, then look which strips don't get dry.

 

[MATTT]

If you look closely at the elements you can normally see either a break if its been rubbed by somethng in the boot or it will be a slightly different colour if its worn through or burnt out,you can gently check with a multimeter on ohms accross it and it will read higher than a good strip,you can buy a small glass bottle of silver repair paint made to repair it,but put 2 bits of masking tape either side as close to the strip as possible as otherwise you get a blob of paint.
If the whole screen isnt working I had one once with a fractured cable so there was 12v when disconnected but it dropped down to 5v as the cable had just a couple of strands still connected so couldnt supply any current

 

[petak]

Here is how you can easily find out where heater is broken

http://www.frostfighter.com/adobe/2400 Lamp Sheet.pdf