Rear heated screen

[gaz1250]

Hi
Rear heated screen not working, re soldered wires that were broke in the boot rubber, light is working at the switch, no reading when checked with volt reader. Fuses under the light haven’t been checked but switch wouldn’t light up if fuse problem? Or would it?

 

[novocaine]

shares fuse with a lot of other stuff so unlikely to be fuse.
check your grounding on the boot lid.
remove plugs from tracks on window and check for continuity and resistance.

light will light up, the defogger is run through the BCS, when you click the switch it tells the BCS to turn it on.

other option is to check the relay hasn't failed.

to be honest, it's a really over complicated system.

 

[Deleted member 31521]

I had partial not working and used a liquid solder on the grid lines on the screen this worked for me they are hard to see so get close to the screen inside and check for any breaks in the tracks.
prior to this had to repair the wiring from one of the connectors they can be really tough to resolder as this may be connected at the glass screen so much care has to be taken in order to solder back it took me a few attempts to get a decent connection once I was happy I checked with the multimeter for continuity and resistance it works now for me but the solder job at the spade connectors are not the most tidy job however it functions and clears the screen properly and no more middle of the screen foggyness

 

[gaz1250]

This screens not working at all, what readings should it bring back on multimeter?

 

[Deleted member 31521]

Mainly I used continuity testing to gather information as to where the line was losing power or a break in the circuit or line.
You need to check that your ground are clean
While checking for Open loop. At the screen disconnect the two connectors and work from one end from lowest to highest point with the other probe connector to the opposite end.
This would help diagnose a break in the element on the screen..
If your issue is with wiring the same rest would be done.
As novo suggested you should check you grounds and to this I can add you should also check your wiring loom up top via the waterproof proofed boot.
Reason being the wires may become broken/frayed.
Most of the time this will be visible by eye and you can make repair as needed.
I reccomend checking that area as most likey it will have suffered or stressed.
An example I have an ebike and the wire was broken recently it shut off the bikes power and when I returned home I found a loose connector and a cut in the wire that reaches across to the battery terminals.
Once you locate the problem a simple solder job would make the best connection long term.
Usually I opt for a butt connector as a first attempt this I use to help show me the item will work then I proceed to repair with solder.
Heatshrink is you best cover if you want a clean finish it is the tidy option and better insulation.

For multi meter set ohm resistance.
An open loop is what you will be locating.

 

[gaz1250]

Thanks will check this at the weekend