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'defect light' indicator lights up (940) 900

After replacing the small lightbulbs in the automatic shifter and ashtray, the 'defect light'indicator in the dash burns constantly.
All lights on the outside (headlights, taillights, brakelights, turnsignallights) work fine and evenly.
I find this peculiar, because to my knowledge the inside illumination of the car is not part of the 'defcet light'circuit.
While i had the ashtray out, i only checked if all fuses were in their places by pushing on them a little bit.

Who can shine a light on this problem ?

kind regards,
John
940 1995 LPT








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'defect light' indicator lights up (940) 900

I had the same problem with my 945. I was finally able to narrow it down to the center stop light in the rear window. Check that bulb, it may just be the culprit.








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'defect light' indicator lights up (940) 900

Kpf,
Thanks for sharing your experience.
I have checked the third brake light, as you suggested and replaced the lightbulb. To no avail i must say to my regret.
The idiotlight is still on.

I'm out of ideas.

Kind regards,
John








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'defect light' indicator lights up (940) 900

Dear John,

May this find you well. I think this is a coincidence. I'd check the bulb burnout relay (round orange unit, at the back row of the relay block) to be sure it is seated firmly.

If that doesn't help, then I'd check grounds for headlights and taillights. Those for headlights are affixed to the inner fender wall, just behind each headlight unit. Those for tailights (in the wagon) are affixed to the inner bumper wall, just forward of the trailing edge of the load space panels, on either side of the load space. I presume the ground points for sedan tail lights are similarly sited.

If the grounds are free of corrosion and tight, then I'd check bulbs for tight fit, absence of corrosion, and pair matches. Bulbs from different makers could have slightly different power draws. A mis-match in a pair of bulbs can trigger the bulb burn-out indicator.

If all of these checks show nothing wrong, the bulb burn out relay may have failed. The solder joints are subject to micro-cracks, far too small to be seen with the unaided eye. You can re-flow the solder, using a 25 watt iron and rosin core solder. Heat the solder for 1-2 seconds, just so it liquefies. At once remove the iron's tip. This can restore a broken connection.

Alternatively, you can get a new relay, or go to a salvage yard and get a few used units. One is bound to work.

Hope this helps. Please post back with your findings.








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'defect light' indicator lights up (940) 900

Spook,

May this find you well and thanks kindly for your always professional advice.
I dismantled the ashtray again and checked the connections. All are ok.
So are the connections to the automatic selector stick .
I took all the tail lights, directional lights, brake lights and parking lights out. They are all A1, fittings are tight and the action did not solve the problem .
All the grounds are ok.
I always have changed lightbulbs in pairs of identical lot and brand.

The only thing i can think of is that some of the bulbs are getting older and start turning brownish, as i have daylight driving lamps.
Could the resistance in the bulbs influence the current, causing the relay to react ?
I have no reason to doubt the relay, but if bad, what other indications should i look for ?

Kind regards,
John







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