Fix my Saab lights 2

Previously, I shared the discovery, analysis, and resolution of a intermittent problem with headlights. That is not the only commonly-found light-related problem on Saab sedans, however. In this post, I will walk through the same process for a common problem with the glove compartment light.



Just as the image (copyright Saab Automobile AB) above illustrates, the light illuminates the glove compartment. It turns on only when the door to the compartment is open. Well, in theory anyway.

There are two different symptoms to this problem. Either the light remains on even when the door is closed, or the light remains off when the door is open. The latter is an inconvenience, but the former is an inherent danger. If the light is on all the time, it will not only drain the battery (so the car cannot start), but also melt the plastic light fixture. What I have is the later.

At first, I wasn't able to find anything wrong with the fixture. The bulb (10 Watt) is fine. The fixture works fine - light turns off when something is pushing against the plastic actuator; light turns on otherwise. Unfortunately, when I put the fixture back in, the light will sometimes fail to turn on when the door is open.

My gut feeling (and experience) tells me that something weird is happening with the actuator. Originally, I thought the failure had to do with lack of interaction between the actuator on the light and the door mechanism. My observations proved that assumption is incorrect. The door mechanism pushes the actuator only when the door is fully closed; the mechanism moves away as the door opens.

A detailed inspection is needed, so I totally disassembled the whole fixture. After a lengthy test session with a multimeter (I avoid using power because the bulb gets hot quickly), I found the problem:



There is a ridge that prevents the springy metal piece from contacting one terminal of the bulb, if the actuator is being pushed at an angle. It's possible to file down that ridge but the location of the ridge is difficult to get at. A Dremel rotary power tool would be very useful in this situation. Unfortunately, I don't own one.



Time for plan B - Keep the ridge, but elevate the contact surface of the bulb terminal with a BloB of solder. Plan B indeed.



The blob of solder, which is electrically connected to the metal piece, is protruding higher than the plastic ridge. Thus, the springy metal piece makes full electrical contact when the actuator is not being pushed on.