Where would you start looking? - PeachParts Mercedes-Benz Forum

Bens lover · #1 09-08-2010, 12:40 PM

Hi guy's.
On my 86 300 SDL the interior lights dont come on when you open the doors.The only one that comes on manually is the dome light above the mirror.Both the rear opera lights and the dome above the rear glass are also inoperative.
I have already checked the door switches bulbs and fuses of course but with no avail.
Any idea out there?

Cheers
Big Dan

4thesporty · #2 09-08-2010, 01:42 PM

These are controlled by fuse 15 in my car, which also controls the underhood light, truck light, vanity mirror lights, and radio antenna.

Are these other things working, or is just the dome light inoperative?

I keep blowing this fuse, so I have no dome light either right now till I can remove all four door panels and inspect the wiring to the lights

Bens lover · #3 09-08-2010, 02:05 PM

Ill have a look at that fuse more closely.I don't have a chart in the fuse box to tell whats what!

Thanks
Dan

Bens lover · #4 09-08-2010, 02:26 PM

Thats so weird...
I replaced the fuse and now all the interior lights come on.But my antenna went down when the new fuse was installed but wont go up anymore....

4thesporty · #5 09-08-2010, 07:55 PM

Quote:

Originally Posted by Bens lover

Thats so weird...
I replaced the fuse and now all the interior lights come on.But my antenna went down when the new fuse was installed but wont go up anymore....

But, do the interior lights come on with the door open now?

If not, the antenna might be causing your fuse to blow. Try cleaning/lubricating the mast, if it is not bent.

Bens lover · #6 09-08-2010, 08:39 PM

Hi Adam
Yes the lights are coming on now.
When I got this car last week,the antenna mast was up only about 6 inches and I did not have time to get to the culprit until today.But the moment I changed the fuse the mast went down and will not go up anymore either by the dash switch or turning on the radio.

bustedbenz · #7 09-08-2010, 08:56 PM

Quote:

Originally Posted by Bens lover

Hi Adam
Yes the lights are coming on now.
When I got this car last week,the antenna mast was up only about 6 inches and I did not have time to get to the culprit until today.But the moment I changed the fuse the mast went down and will not go up anymore either by the dash switch or turning on the radio.

I do NOT think you are an ignorant benz owner but I just want to ask this question to rule out the obvious. Are you sure you're testing it with the knowledge that the antenna only works with both the ant switch on the dash in an on position AND the car radio on?

In other words -- the antenna switch has to be in the upwards or center position before you turn the radio on. Then, when you turn the radio on, the antenna should come up to meet its switch position.

I'm sure you knew this but you described testing both functions separately but not as a pair. Just checking.

And to "4thesporty": Before you take the door skins off and risk their refusal to go back together, open the doors and check the door sill courtesy lights to see if one has fallen out. The little plastic lights can come un-pressed from their little sockets and fall out and then get slammed between the door and the frame. Ask how I know. When this happens, the wires can be made to short out against each other or the frame, and then the fuse blows. This is an easier thing to check and rule out than pulling those fragile door panels off. After a few times on and off, mine are all getting pretty ragged.

4thesporty · #8 09-08-2010, 10:23 PM

Quote:

Originally Posted by bustedbenz

And to "4thesporty": Before you take the door skins off and risk their refusal to go back together, open the doors and check the door sill courtesy lights to see if one has fallen out. The little plastic lights can come un-pressed from their little sockets and fall out and then get slammed between the door and the frame. Ask how I know. When this happens, the wires can be made to short out against each other or the frame, and then the fuse blows. This is an easier thing to check and rule out than pulling those fragile door panels off. After a few times on and off, mine are all getting pretty ragged.

In an attempt not to hijack this thread I will make this answer short;

I think I have found the culprit, the drivers door light.....with a good fuse in if I pull the wires from the light socket I read ~12 volts, however when I plug the wires into the socket and read where the light "clips" into I get nothing...weird.

I'm going to switch driver/passenger light socket and see if that cures it.

vstech · #9 09-08-2010, 10:41 PM

usually the lights are switched to with ground. so you are measuring ground to ground possibly. keep that in mind when testing.

Bens lover · #10 09-09-2010, 09:19 PM

Ok guy's lets clarify this whole story.

First. I had an issue with the interior lights not coming on at all.
Second. I did not have a fuse chart but someone was kind enough to tell me what fuse I was looking for(#15).And it so happens to be the culprit.
Now that the interior lights work properly,my daughter noticed that when I replaced the defective fuse the radio antenna went all the way down.It was originally about 6 inches above the fender.Now the new issue is the radio antenna is not functioning at all.
Does anyone have any clue what the problem could be?
Since it was already 6 inches up before the fuse burnt out.

Regards

Big Dan