Rear window demister

No it can't.

There are only 3 things to look for, 1, is there power at demister checked with a volt meter on the wire connector on the back window. 2, is the earth wire connected again with a volt meter at the back window. and lucky last,3, check the ohms on the back window

The official workshop manual Suggests:

1. Close the doors.
2. Turn the ignition key to the accessories position.
3. Within 5 seconds of turning the key, hit the rear demister button (center console) three times in succession.
4. The door locks will cycle once to indicate the special mode has been entered.
5. Press any button on the remote you wish to program.
6. The doors will cycle to indicate a new remote has been programmed.
7. Continue steps 6 and 7 for all remotes (including existing ones) you intend to use on the vehicle.
8. When you've programmed all the remotes, turn the ignition key off. The doors should cycle again to indicate the programming session has been completed.

you know those little brown lines on the inside of your rear window, they are wires and can get damaged when cleaning your window. get an OHMS meter and you can actually test the lines on your glass and find the damaged sectors, you can get repair kits to do repairs

have you tested the switch it could be your fault

Most likely a chaffed wire in the door hinge area.

on a 1997-2002 caldina G, GT, GTT..

One is the rear demister (front demister is in the center console with the heater). But it could also be the windscreen cleaner pump, if you mean on the stalk. (up, front window, down, reap window).

One is the fog lamps if fitted

The last is an inverter buit into the car so you can run 100Volt domestic devices (like laptops/shavers and stuff). I think the japanese have 100 volt domestic power. You'll find the *** power socket on the back of the centre console under a little hatch, easiest to see from the back seat. Mostly you want it turned off.



Ray.

You do not say what brand and model vehicle you have.

The rear window demisters drain a lot of power and are usually programmed to switch off automatically after about 15 or 20 minutes of use. They should also cut out fully when the vehicle's ignition is turned off and of course when you manually switch them off.

1. When you are driving and running a host of electrical units simultaneously in winter there is maximum power drainage and any shortfall in power from the alternator has to be drawn from the battery. This will be a problem if you have a weak battery that is not holding it's charge well or if the battery is not fully charged once it has been nearly or fully drained. It will also be a problem if the alternator is not producing it's optimum power while the vehicle is running.

Batteries do not respond well to being drained frequently and when they are they should always be fully charged again each time with a battery charger at the earliest opportunity. (Running them down and then expecting the vehicle's alternator to do all the battery recharging is not a sound practice).

2. It is possible the rear demister is not shutting down automatically after a period of operation as it is likely to be programmed to do in your vehicle. This is easily checked. If it is not shutting down, and the battery is needed to supplement the vehicles power supply when driving, then the battery can be run down in time.

3. If the rear demister is left active but not shutting down when your ignition is turned off your battery will quickly drain.
You should check that power to the rear demister is off once the ignition is switched off (and when you switch the demister off manually). This is unlikely to be a problem but in the unlikely event that you find it is still operating then you can pull the fuse dedicated to the rear demister.

I hope this helps.

Check rear demister control relay operation,
Check for presence of 12V power (and ground connection) at rear window heater connection.

Check continuity of the rear window heating element.

Do you have rear window tinting?( the plastic sheet type ) If so,check that the edges over the demister tapes have not curled up pulling the tapes off the window and diconnecting them. If they need repair, a small bottle of tape repair solution should be available from a spare parts retailer.
El Nombre