Intriguing HRW problem

[martinchambers]

Only lines 3&4 of my HRW are working (Corsa D 57 plate) and I can see no visual damage. I would really appreciate any help in trouble-shooting this odd problem. The fact some lines are working would seem to indicate it's not the fuse or the relay?

Continuity tests (looking at the car from behind):
- all the lines are continuous from left to right across the glass.
- all the left hand edges of the lines are continuous with the left hand terminal (+12v).
- all except the bottom line (line 1) are continuous with the RH (earth) terminal (could this explain the symptoms??).

Voltage tests:
- at the LHS lines 1,3,4 & 14 have 12+v, all rest have ~0.27v
- at the RHS line 1 has 12+v, lines 3,4&14 have ~0.7v, rest have ~0.24v

At the edges of the glass the conductive paint lines disappear under a broad band of some kind of lacqer so I am unable to look for, or test for, breaks in circuit. But then again, being under the lacquer and protected by a rubber seal there should not be any damage? Am I right in thinking that all the horizontal lines are joined by vertical lines at each edge under the lacquer?

Any ideas gratefully received.

 

[Belle427]

if your sure the horizontal lines have no breaks then you must have a problem on the vertical link lines, it only takes a light scratch with something to damage them.
I would try to expose the area where the wires are connected and examine there, they are wired so that damage to a horizontal line allows the rest to work

 

[Mursal]

From memory all lines are in parallel, so you should have 12 volts dropping across each one.

Hope this helps

But if its not obvious you will need a screen