Display shows my tail lights out????? [Archive] - SaabCentral Forums

: Display shows my tail lights out?????


9000s_91
11-01-03, 11:38 AM
The display on my dash has shown my tail lights as being out ever since I bought this car. I've replaced all the bulbs including the brake lights on the rear window, but the display still shows them as being out when I turn the headlights on.

How do I troubleshoot this problem?

Thanks.
tom

9000s_91
14-01-03, 09:02 AM
Does anybody know how that system works? Has to be one big brain out there someplace....come on UK, don't let me down.

tom

BillJ
14-01-03, 09:25 AM
The filament monitor checks that the current across a pair of bulbs is in balance. For example, if one of the taillights goes out, there will be more current flowing to one side than the other and it is this condition which lights the warning lamp.

If all bulbs in a particular circuit are healthy, this condition can be caused by a bad contact, loose bulb or bulbs of mixed manufacture in a set.

Steve Brown
14-01-03, 10:33 AM
Hi,
Had just that problem in my '93 9000 CD. All the lights functioned, but I got the warning light on all the time. I got the cure from a member of the SAAB Net <http://www.saabnet.com/tsn/bb/9000/>
No excuses for posting it.
The problem was the resistance differential caused by the varying rates of oxidation of the bulb-recepticals. Clean all bulb holders, WD-40 them and you'll have no further problems.
Steve

BillJ
14-01-03, 12:37 PM
No excuses for posting it.
No problem, Steve. We don't censor any links on SaabCentral, as long as they are relevant. It's all in the spirit of sharing information with other Saab owners around the world.

9000s_91
14-01-03, 01:48 PM
Thanks Steve. I put all new bulbs in from all new packages from the same manufacture. I think my tail light has been replaced in the past, so I'm wondering if that could do it. I took ohm readings across the bulbs with them in place, and didn't see any differences, but I'll shoot some WD-40 on there and clean them up. Hopefully this will fix my problem.

Swedishdynamics3
14-01-03, 06:30 PM
I have the same problem on my 94 9000 and I have checked recalls and there is one for faulty wiring with the tailamp indicator. Might want to consider that.

9000s_91
14-01-03, 08:03 PM
How did you find that recall? I'd like to know what the dealer will do.

Tonight I took both tail light assemblys out and measured ohms across all the bulbs. All the ohm reading are exactly the same from one side to the other.

I can get the indicator light to go out if I pull the two filament bulb out of both sides (it goes out) and put one back in (indicator light comes on) and then put the other light in (indicator light goes out). But as soon as I turn the dash knob off and back on, the indicator light comes back on. I give up.

I'm going to try to find that recall item. Sure would be nice to figure this one out. I'm about ready to pull my hair out. I even cleaned the grounds and put some WD-40 on the bulb contact after cleaning them all with 1000 grit sandpaper.

tom

Swedishdynamics3
14-01-03, 08:40 PM
Here is the website http://www.alldata.com/TSB/52/86520302.html
hope this helps