rear demister switch help

[Vinny]

Thanks for all the help folks be lost without you .
My car is a 1990 coupe the lights defo stay on for more than two minutes is it possible someone might of hard wired them to be on a constant live .I will re check tonight as I can't see them trough the day...

[Vinny]

Right guys ive just been out to look inside my car and all the electric window switches are lit up , the car has been locked all day .
Not sure if this will make a difference but the boot central locking dosent work it only works off the key, but has also been locked all day..

[S2central.net]

Annoyingly - I don't yet have the MY90 schematics for B3 Coupe - I recall some grief getting them in the past but I will look at the nearest diagrams I have. Does your car have the factory fitted alarm ?

[S2central.net]

So… the central locking circuit is a red herring here - had to look for a reminder… the 12V supply to the window switch lamps is actually from the electric window relay which should only apply 12V to the red/blue wire in the switch loom when key is on (ignoring timers for doors etc after key removed).

http://www.s2central.net/S2_Schematics/D/D32.PDF shows MY92 Coupe wiring for this - you can see how the drivers door switch (F2) is in play and how the 'X' contact tells the window relay if the key is at the ignition position or not.

I bet your windows go up and down while the key is removed too.

The window relay is the big fat one at position 5/6 above the drivers pedals - removing it should make your window switch lights go out - and your windows inoperative as well of course.

If you have access to a simple voltmeter you could remove the window relay and do some simple tests to check things are as they should be.

[Bowie69]

Yup, sounds about right, my '91 allows you to put the windows up until you lock it or for something like a minute, which ever is sooner

[Vinny]

No alarm that I am aware of no sensors anywhere that I can see !!

[S2central.net]

Like I said - forget the alarm thing - its a red herring. I have a theory that your X-contact relay might be stuck ON… go to the main fuse box and pull out relay number 5 (five)… then tell me if your window switch lights are still on !

[S2central.net]

Some simple checks to make at the pins of the window relay module are as follows pin by pin -

01 black/blue should be 12V only when key is at ignition position (this is energised by the X contact relay)
02 red/black should be 12V permanent
04 blue (where fitted) should be ~14V when engine running only
05 brown/yellow should be open circuit or 0V depending on drivers door switch
08 red/blue is the 12V supply to window switches when the relay is energised (key ON)
14 brown is 0V earth

[Vinny]

Right paul I think I have some pics to upload but not sure how to do it just been out and looked in the fuse board and its deffo hard wired with constand live cos ive disconected this and the lights have gone out ! How do I upload pics of a mobile , or do you have an e mail I can send these pics to you....

[S2central.net]

You can send mail to S2central@mac.com …. Do I understand correct that you unplugged Relay #5 in the main fuse box and the window lights went out ?

If so then you probably have a dicky/sticky X contact relay - its a very common ordinary pattern part… it supplies switches 12V to lots of accessories on the car so you need it working properly or you will have potential battery drain problems with things active that don't need to be… swap the relay temporarily with another 4-pin item in the fusebox to prove the point then pick a fresh one up from any decent motor factor (or halfrauds etc)

[S2central.net]

For example - your headlights should only come on with key in the ignition position - this is triggered by X contact - mainly to spread the current load over multiple wires and avoid huge / silly / expensive ignition switches that need to pass all the switched loads.

[Vinny]

Sent pics via e mail.
Cheers vinny

[S2central.net]

Ok - your pics show the relays above the drivers pedal. Keep that big relay 262 in place and turn your attention to the main fusebox in the engine bay.

Then remove relay #5 from the main fusebox and tell me if the switch lights go out.

[Vinny]

Right I have pulled the relays under the bonnet nothing so I proceeded to pull the rest of the fuses
My no 20 , 30a fuse turns them off which is 1st cooling fan delay fuse..
where is the window relay and what no is on it?
Cheers for the help I think some previous owner has been tinkering!!!

[S2central.net]

Don't believe what the fusebox cover tells you ... I need to look what fuse 20 is really for. Window relay is that big fat one numbered 262 on your car above the pedals.