How to trace broken elements on a heated rear screen
Discussion
So I've fitted a new top tailgate on my old rangie. Its ali so it won't rust, its also a bugger to keep shut it turns out!
Also there only appear to be 1 or 2 lines working on the heating element. Now a cursory look doesn't show huge gaps so its going to be out with a mulitmeter to find the gaps and fix with conductive paint.
So how do I test the individual lines and find the gaps?
I'm guessing that looking for a circuit between 2 points won't work as its a continuous circuit if any lines work.
Also there only appear to be 1 or 2 lines working on the heating element. Now a cursory look doesn't show huge gaps so its going to be out with a mulitmeter to find the gaps and fix with conductive paint.
So how do I test the individual lines and find the gaps?
I'm guessing that looking for a circuit between 2 points won't work as its a continuous circuit if any lines work.
DKL said:
Oh so funny. I was after someone who knew how the meters worked to explain it in a little more detail rather than the local joker.
The second one I had found already.
It's such a simple operation I thought you hadn't googled it yet.The second one I had found already.
Which part are you struggling with?
You start at both ends and just work the ends together until you isolate the break.
It gets more fun when you have two breaks in the same line.
ETA: How I understand it is the heater is made up of high-ish resistance lines. When you put the meter across a line with a break in, the meter has a lower resistance so the voltage "floods" through the meter. When you put the meter across a good line, it is in parallel with the resistance so therefore shows a lower voltage.
Edited by jhfozzy on Thursday 6th November 14:56
jhfozzy said:
It's such a simple operation I thought you hadn't googled it yet.
Which part are you struggling with?
You start at both ends and just work the ends together until you isolate the break.
It gets more fun when you have two breaks in the same line.
ETA: How I understand it is the heater is made up of high-ish resistance lines. When you put the meter across a line with a break in, the meter has a lower resistance so the voltage "floods" through the meter. When you put the meter across a good line, it is in parallel with the resistance so therefore shows a lower voltage.
ok thanks. Thing is its simple if you know how! Your second link measures voltage but I had it in mind I'd be measuring resistance or lack of.Which part are you struggling with?
You start at both ends and just work the ends together until you isolate the break.
It gets more fun when you have two breaks in the same line.
ETA: How I understand it is the heater is made up of high-ish resistance lines. When you put the meter across a line with a break in, the meter has a lower resistance so the voltage "floods" through the meter. When you put the meter across a good line, it is in parallel with the resistance so therefore shows a lower voltage.
Edited by jhfozzy on Thursday 6th November 14:56
Instructions are all well and good as long as what it says will happen, happens. When you get a different result you're back to square one.
I'll give it a go with your theory in mind.
Thanks
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