MR2 Roadster Owners Club

The Workshop => Audio / Security / Electrical => Topic started by: Anonymous on December 10, 2006, 12:14

Title: heated rear window circuit - for you techy guys?????
Post by: Anonymous on December 10, 2006, 12:14
As part of moving various switches on the dash I am left with the heater control unit air con and h/r/window switches to re-locate.

The circuit board for these two switches is quite complicated and includes a multit connector with around 12-16 different connections.  I'm assuming that it is this complicated due to timer/delay functions?

In principle both the aircon and heated rear screen should really only require on and off functions with ideally a warning light for each to show that they are in use?

so.......for the rear window is it just a case of running 12 v through the element via an independant switch? or is it more complicated than that?

I seem to remember in the old days when you fitted a heated rear window kit to a car without one (stick on), it was just an illuminated switch, no fancy resistors or circuits?

any idea wizzkids?

I'll come to the air con later   s;) ;) s;)
Title: Re: heated rear window circuit - for you techy guys?????
Post by: Tem on December 10, 2006, 15:58
Quote from: "perry190"The circuit board for these two switches is quite complicated and includes a multit connector with around 12-16 different connections.  I'm assuming that it is this complicated due to timer/delay functions?

In principle both the aircon and heated rear screen should really only require on and off functions with ideally a warning light for each to show that they are in use?

so.......for the rear window is it just a case of running 12 v through the element via an independant switch? or is it more complicated than that?

Yes, it basically just needs 12V.

I made notes about the whole system a while ago, but can't seem to find them right now. IIRC, the switch is routed to commonly available timer chip, where you can even change the time if needed. One push arms it and the 2nd disarms, the switch gives just a signal when it's down.

If you want to keep the stock usage, you can reuse the timer chip. Just google it with the part number and you'll get the wiring info for it.  s;) ;) s;)
Title:
Post by: Anonymous on December 10, 2006, 16:37
cool, thanks Tem.

I'll run the heated rear window to an independant illuminated switch then, no probs  s:) :) s:)   (not worried about timer delay as long as I have an 'ON' light)

I'll then trace the air con circuit and try the same

My turbo timer should be here on Tuesday (Greddy) I'll let you know how I get on with that (as a comparrison with your problems)
Title: Re: heated rear window circuit - for you techy guys?????
Post by: Anonymous on October 6, 2008, 15:00
Hi, any help will be much appreciated

Im having trouble with the heated rear window, basically i press the switch on, the switch lights up but it does not demist my rear window.

yes i have plugged in the lead to the roof

Where can i find the fuse for this and which one is it

Any ideas why its not working before i make a trip to the autoelctrician

Many Thanks
Title: Re: heated rear window circuit - for you techy guys?????
Post by: Anonymous on October 6, 2008, 15:12
Fuse box for instrument panel no.13 gauge 7.5amp but does a lot more than rear window defogger so i doubt it is the fuse.
Title: Re: heated rear window circuit - for you techy guys?????
Post by: roger on October 6, 2008, 15:23
Is this on the hard top or soft top? If hard top, was it working for soft top?

<edited> The fuse is the top one in the middle column, in the fuse box by passenger door. DEF @ 25 amps, supposedly works the back window defogger. Failing that, there are a couple of relays which I can locate but know nothing about.

I'm guessing the one Craig refers to above is for the switch light only, though I would have thought somehow they would have been connected.
Title: Re: heated rear window circuit - for you techy guys?????
Post by: Anonymous on October 6, 2008, 15:41
Thanks for the replys guys

Its for the hard top roof, i never tried to operate it with the soft top, i just need it fixing before winter sets in

I have tested the plug that goes into the roof and no power wotsoever

The light on the switch lights up when switched on

I have left the connector connected in the soft top is this correct, as i tried with it disconnected and still nothing (i hope this makes sense)

Roger ive checked that fuse and its perfectly fine

Craig, sorry to be a pain but how can i find this fuse as i dont have a manual, can you point me in the right direction

Any other suggestions

Thanks
Title: Re: heated rear window circuit - for you techy guys?????
Post by: SimonC_Here on October 6, 2008, 16:12
Not got a hard top but don't you plug the cable that normally goes in the softop into the cable that goes into the hard top?
Title: Re: heated rear window circuit - for you techy guys?????
Post by: Anonymous on October 6, 2008, 16:17
Hi

The cable that goes into the soft top is to short to reach the hard top, thats why there is a much longer lead thats available to reach, plus im sure its a different connector aswell.

Thanks anyway

Kev
Title: Re: heated rear window circuit - for you techy guys?????
Post by: SimonC_Here on October 6, 2008, 16:21
Check out page 6 of the pdf referenced here:  l viewtopic.php?f=46&t=13446 (http://www.mr2roc.org/phpBB3/viewtopic.php?f=46&t=13446) l
Title: Re: heated rear window circuit - for you techy guys?????
Post by: SteveJ on October 6, 2008, 16:22
Quote from: "kevhky"Hi

The cable that goes into the soft top is to short to reach the hard top, thats why there is a much longer lead thats available to reach, plus I'm sure its a different connector aswell.

Thanks anyway

Kev

and did you plug both ends in? One on the hardtop, one down the side of the bin (remove the side panel to get at it)

Have you RTFM?
Title: Re: heated rear window circuit - for you techy guys?????
Post by: Anonymous on October 6, 2008, 16:25
Open the passenger door, at the side of the glovebox next to an airbag sticker is a fuse box behind a clip out panel, tells you on the back of the panel which fuse is which.
Title: Re: heated rear window circuit - for you techy guys?????
Post by: Anonymous on October 6, 2008, 16:27
Quote from: "SteveJ"Have you RTFM?

He has already said that he does not have a manual.
Title: Re: heated rear window circuit - for you techy guys?????
Post by: SteveJ on October 6, 2008, 16:40
Quote from: "nelix"
Quote from: "SteveJ"Have you RTFM?

He has already said that he does not have a manual.

I actually wanted to ask have you UTFS but that is now un-PC.
Title: Re: heated rear window circuit - for you techy guys?????
Post by: Anonymous on October 6, 2008, 16:41
ALL SORTED

Thanks very much everyone for the help

You will laugh

The lead that plugs into the hard top, well the other end was just dangling loose behind the side panel in the rear rh bin.

No wonder i wasnt getting any power.

Once again thanks alot

Id probably never have found it without your help

This is defiately a forum to stick with

Regards

Kev
Title: Re: heated rear window circuit - for you techy guys?????
Post by: SimonC_Here on October 6, 2008, 16:48
Quote from: "kevhky"ALL SORTED
You will laugh
Yes, yes we will, and probably point as well!   s:lol: :lol: s:lol:    s:wink: :wink: s:wink:  

Just for future reference, if your passenger window stops working, check the little push in switch to the right of the steering wheel first!
It's surprising how many people that catches out.

Simon
Title: Re: heated rear window circuit - for you techy guys?????
Post by: Anonymous on October 6, 2008, 18:19
I knew that one Simon

Thanks anyway

Why on earth would you want to be able to stop the passenger opening the window - it beats me

Regards

Kev
Title: Re: heated rear window circuit - for you techy guys?????
Post by: SimonC_Here on October 6, 2008, 18:24
Reach over and slap the passenger, that's what I say!  s:) :) s:)
Title: Re: heated rear window circuit - for you techy guys?????
Post by: Tem on October 6, 2008, 20:22
Quote from: "kevhky"Why on earth would you want to be able to stop the passenger opening the window - it beats me

I've heard it can be useful, if your passenger is a restless kid. But that's with a normal car where the switches are in the door. Seems kinda useless in a 2 where both switches are in the middle.
Title: Re: heated rear window circuit - for you techy guys?????
Post by: davidhowson on October 7, 2008, 21:01
Believe me, it's VERY useful to stop restless 6-year-olds opening and closing the window. Wish there was a button that could mute her volume too   s:lol: :lol: s:lol: