heated rear window

[paul d]

Originally Posted by humptynumpty

I'm feeling dumb as I read that link and made no sense lol maybe to tired, so where is connections on rear screen to check and best earth??

You get to the connctors by removing the pillar trim to the left of the parcel shelf viewed as you're looking backwards out of the car. If memory serves theres an earth behind there as well.

Regards

Paul

[humptynumpty]

Ok buddy just checked with nephew working button and on both connections on screen to earth I got 0.03-0.05v when button on and 0.00v when off so it would apear there is a circuit with power getting to window, so would problem be in window itself?

[SD1too]

Originally Posted by humptynumpty

... on both connections on screen to earth I got 0.03-0.05v when button on and 0.00v when off so it would apear there is a circuit with power getting to window ..

Err ... no Mark, quite the opposite in fact.

Are you looking at a module labelled XUE 100 001 with two black wires and one brown?

Simon

[humptynumpty]

Yeah mate but the brown wire is badly oxidised and breaking up

[paul d]

Hi Mark

If Simon is on the case go with him. I would never have sorted mine or a couple of other things without his help. Top man.

How are you Simon. Hope you're well.

Don't suppose you will be at Elstree a week Sunday? I haven't forgoten i owe you a pint.

Regards

Paul

[neilbaker86]

You need to remove the R/H rear quarter trim (this is the left hand side as you sit in the rear seat looking backwards).

On mine, there is one thick Brown/Green wire going to a black box, this is a junction box as there are two separate elements. Place the red probe of your multimeter set to DC volts onto any of these wires, you can simply disconnect the connector with the thick brown/green wire and probe into the end. Then stick the black probe of your meter on to a good earth (can use the earth wire behind the other quarter trim if you like) and turn the HRW on and you should get +12v. If you don't, you have a missing supply.

If you do get +12v. Then you need to switch the HRW off and set the meter to measure resistance (ohms Ω) and measure the resistance through the HRW circuit to earth. If it's open circuit (meter may display O-L), there's your problem. Causes for this are either damage to the element printed onto the glass, such as a scratch, or more likely damage to the soldered terminals at either the supply side or the earth side.

Note you need to have the engine running for the HRW to work. There are other certain conditions under which the LED will illuminate to say the HRW is on even though it isn't, this is when the battery voltage is too low, and the BCU won't allow it.

[SD1too]

Originally Posted by humptynumpty

... the brown wire is badly oxidised and breaking up

I think you've found the problem then Mark. You'll need to cut it back to expose clean conductors then extend it if necessary.

Simon

[humptynumpty]

i connected the multimeter to the oxidised cable and to earth and i was getting 14.58v and if i check ohms im getting nothing to any cables or screen connections but there doesnt look to be any damage

also car has had a new battery and alternator in last 2 months and car diagnostic says its charging at 14.6 volts and battery is holding well over 12v

also if they are both supplies is the earth side the other side of car?

[SD1too]

Originally Posted by humptynumpty

... the brown wire is badly oxidised and breaking up

Mark,

Don't allow yourself to be distracted by other things. If the brown wire is in poor condition you need to renew it. Oxidation and physical damage will introduce electrical resistance which, with a the large current a HRW draws, could result in a significant voltage drop.

So never mind the battery, the alternator or the location of the earth. Mend the brown wire!

Simon

[humptynumpty]

well the damage is right up to plug end so can cable/plug be obtained mate and there was 14v at the oxidised plug but nothing at black plugs so were is volts/ohms going??