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Slower sunroof and dim interior lights
Posted: Wed Jan 14, 2004 8:42 pm
by THAWA
About a month back I stopped using the sunroof in my car since I wasn't driving it. It sat for about 2 weeks with no use. Then when the car was drivable again, I went to open the sunroof, it was very sluggish. I figured it was just because it hadn't been used in a while and it was pretty cold out that day, so I didn't use it again until the next day when it was about 20 deg warmer. Still it was stiff. I tried working it back and forth many times yet it still is kinda slow. What could be the problem? motor dieing? track needs cleaning? Or am I just overreacting, and I should wait until warmer weather?
My second question is, I noticed a while back that the dome light is a lot dimmer when it's activated by the door than when I manually turn it on. I'm thinking it might be because when you put it to the on position it is grounded about 3 inches away. But if the dome light is so dim, what else isn't getting that much power? Is there anyway to make it so the electronic are more efficient inside the car? A new ground point? or maybe clean the original one? If the original one where is this located?
Posted: Wed Jan 14, 2004 10:36 pm
by vrg3
If I'm interpreting the wiring diagrams right, both the dome light and the sunroof motor ground through their bodies which are bolted to the roof. Maybe you could get a length of 10 or 8 gauge wire and run it from the body of the sunroof motor to a good ground elsewhere. Or just look for corrosion and stuff and clean it up.
Posted: Thu Jan 15, 2004 3:47 am
by THAWA
do you mean when the domelight is in the on position? If so that's not the problem. That's the brightness I'd like, at least. The problem is when it's in the "door" position, and you open a door, it turns on and everything fine, but just isn't as bright as when the light is in the on position.
Posted: Thu Jan 15, 2004 3:56 am
by vrg3
In all of our cars it's brighter when the switch is on than when the door's open. That's because when the door opens the light grounds through a long wire going all the way to the instrument cluster and through one or more diodes in the instrument cluster. The diodes and long wire cause a voltage drop. That's normal behavior.
Posted: Thu Jan 15, 2004 4:20 am
by THAWA
well thats weak, is there anyway to shorten the wires a bit, like near a few things, like instead of a wire going all the way to the in cluster, ground it about half way and have that wire go to the cluster? would that work?
Posted: Thu Jan 15, 2004 4:26 am
by vrg3
The diode voltage drop'll still get you. It's the majority of the cause anyway.
You could rig up a relay to drive the bulb, but it would probably be more trouble than it's worth. Does this really bother you?
Maybe you can get a higher-wattage or higher-efficiency bulb... I'll look into it.
Posted: Thu Jan 15, 2004 4:36 am
by THAWA
it bothers me somewhat (not enough to spend more than 10 bucks fixing though

), but what bothers me more is whether or not other things are getting less power/energy than they should be.
Posted: Thu Jan 15, 2004 12:29 pm
by THAWA
okay tonight, I opened the sunroof while coming home. When I tried to close it it went to the finger safety stopping point fine, though still a little slower than usual, then after that it was MUCH slower than normal, it took like 3 seconds to go from the finger safety stop area to the fully closed position.
So what do ya think, motor? How can I test this? Would I be able to just clean up this one in a similar fashion to what others do for the sticky power antenna?
Posted: Thu Jan 15, 2004 6:18 pm
by vrg3
Hmm... Could be anything. Gunk in the rails, or a bad ground, or degrading wires...
It certainly couldn't hurt to clean the moving parts out.
If you feel like removing your headliner, you can measure the voltage between the positive side of the battery and the blue wire of the sunroof motor (while the motor is turning). If it's significant, thats part of the problem but isn't trivial to fix since the blue wire goes to the sunroof/window relay under the driver's seat.
You could also measure the voltage between the chassis of the motor and the engine block while it's working. If it's significant, a big grounding strap could help.