07-03-2000, 09:02 AM
I have a problem re computer display on my 1996 car, which means it is so faint as to be virtually unreadable in daylight. When ignition is off, the display button shows a bright clock display, but this is lost when ignition is switched on.
Is this a failing of the unit, or a standard defect in design?
The computer display - have you got the fancy one (digital clock as opposed to analogue) that does speed warnings, miles to destination etc.? And do you mean this bit of the display, as opposed to the bit at the bottom of the dash?
There should be a light sensor in one corner below the clock - hold your thumb over that and see if that makes any difference? I've heard of this failing in someone else's car.
Does the brightness problem apply both to the clock and the display at the bottom of the dash?
I'm not aware of it being a standard design problem.
I'll dig around and see what I can find...
07-04-2000, 10:15 AM
Yes it is the digital one and yes the problem is also with the display at the bottom of the main instrument dash; the trip computer bit.
I'll try the tip about covering the light sensor; I guess that may have failed and that would affect both displays would it? The night lighting of the instruments themselves is fine.
Is the sensor replaceable separately or is it a whole new unit? (I bet I know the answer to that one knowing my luck!)
Thanks for your interest
07-04-2000, 11:19 AM
Yes, the little photo-chromic magic eye in the bottom corner of your clock/computer controls the brightness of both the clock display and the dash display for fuel consumption / miles remaining / ambient temperature / volts etc.
The 'eye' is tiny and is recessed in the centre of the little button, so it's prone to collecting dust or polish when you wipe over your walnut!
Before you spend a million on a new one, carefully clean out any foreign matter from the recess to reveal a perfectly clean eye. Any tiny amount of matter in this recess will reduce the light falling on the eye and your computer will think it's dark, so dimming the displays for night use.
Hope this saves you an arm...
The gent I know who had the problem had the 'luxury' of swapping the units from his old car (write-off) to tit's replacement.
Perhaps a slightly better test method would be at night, with a small torch to illuminate the eye - otherwise it's very hard to see the change in brightness of the displays (not that it hasn't kept me amused during the day trying to see the change!).
I've absolutely no idea how much they cost - but I would be inclined to agree that it's likely to only be sold as an entire unit. There will be links from The Saab Pages to numerous dealers who could tell you (ask about Owners Club discount if applicable).
Worth bearing in mind - if you can wait - is Splash Out On Spares (SOOS) hosted in the Midlands in May. Probably one of the better bets for getting one at a reasonable price. Also consider dismantlers - but I've no experience of them myself.
P.S. Unless you know an electronics whizz who likes photocells!
07-11-2000, 08:58 AM
Hi Phil etc,
I think you guys are up the wrong drill with the EDU display. It is backlight with a couple of (or is it three?) tiny bulbs. My guess is that these need replacing. Unfortunately the top has to come off the dash and the instrument panel removed to get at them. They are 1.2W mounted in a plastic bayonet fit holder and cost about 40p each from motor factors.
07-11-2000, 10:52 AM
I think I'm talking a load of tosh in that previous reply. I hadn't read the message properly so didn't take in that there is a DCC unit in place of the clock. I don't think however that the photocell is really the problem. The variation in illumination provided by the photocell is really quite small. It may be that the circuit which the cell drives has packed up or there may be a logic fault of some kind. On the standard EDU without the DCC you can turn off the display by by pressing the INFO and RESET buttons simultaneously. Is there a similar function with the DCC?
Just had a look in the manual (which was right next to me, so didn't waste any energy!) - no mention of a way to turn the DCC display off, whereas it does mention how to turn off the EDU.
07-17-2000, 09:12 AM
Thanks all for your comments. Having mentioned problem at servicing last week, advice is that the sensor is defective (though I'll try cleaning the eye to be sure) and that a new unit is needed. the good news is that having bought used via SAAB dealer it is covered by guarantee, they think anyway.
Its a silly problem, not so serious as to be a problem driving but makes the edu redundant when driving, so I want to get it fixed...
Will post further info if and when replaced.