Fuse #43 keeps blowing

[LukeG]

ok so what does this fuse link to? My windows and sunroof do not work.

i know i have a short somewhere, but where do you guys think i should start looking?


95 m3

[LukeG]

i love bf.c

i searched and serched and i ended up checking my trunk wiring and it was frayed...fixed it and the fuse stopped blowing and windows work.

the thing i was really worried about was that i just installed a audio system...swapped the engine and r&red most of the interior. And all of a sudden that trunk wiring became a issue....weird

[Bondanero]

Im pretty sure I have the same problem. My sunroof, vanity lights, and windows do not work. How do i get into my trunk wires?

[madviii]

Open the trunk..... I think the harness runs down the left hand side (standing behind the car facing the trunk) trunk strut. Apparently the wiring inside the protective sheath gets frayed.

[LukeG]

like madvii said, you have to remoce the tape thats covering the wires, repair broken ones and retape the bundle

[M-technik-3]

Mine was the vanity light bulb was causing fuse to blow. Strange that those small lights are wired into the circuit.

[Bondanero]

I have a 99 M3 Coupe.

So i found some frayed wires, they were not bad at all. I put duct tape around them. Didnt fix my problem

I then replaced the comfort relay. Still didnt fix my problem.

Fuse 43 still keep blowing everytime i turn my car on. Any suggestions?

[Da Infammus 1]

Im having the same issue. I noticed that the vanity light for my drivers side mirror doesn't always turn off, I think it has something to do with that.

[thecaines]

For whatever reason on an E36 (mine's a 97 sedan) the window switches are connected to the interior lighting circuit for the vanity and map lights. After blowing many Fuse 43s, I found the problem! The metal of the vanity light near the bulb can touch the metal roof. The ground connection is able to pass much more than 5 amps, so the fuse blows. I put electrical tape on the roof inside the vanity light hole and that fixed it. Turns out I recently had a headliner replacement and they didn't push everything in all the way. As I pushed on things to make sure they were fully seated, I must have pushed the vanity light up against the roof and it stayed in contact. I didn't realize it until I tried to put a window down, and none of them worked.

[bigmouthwoman]

Thanks to THECAINES~! Your diagnosis is exactly right.

I did headliner replacement on my 1995 bmw 320i and the new headliner was not with the holes for vanity lights. I made two holes for them and finished the headliner work. I started the engine and then
1) vanity lights were gone
2) reading lights at interior lights were gone
3) all window lifter swithes did not work
4) airbag warning lamp were on and stayed for around 5 min.s and off
5) #43 fuse was gone - 2 times.

FINALLY
I unscrewed the sun-visors with mirror covering, sun-visor brackets and vanity mirror lamps and
checked any metal contacts on the roof to make a short. I put some duck tapes on the roof/metal parts in sun-visors and all came all right~!

The SOLUTION was
to eliminate ANY metal contact onto the roof or metal body part;
I replaced the blown fuse and ALL CAME RIGHT.

ADDITIONALLY
I CLEANED all contact points like bulbs, clips and switches, with wax/grease remover and the other faulty ones came all right~!!

BUT one problem still stays on AIRBAG warning light, which I have to tackle with from now on:-)

Thanks

[ctung]

When the problem started I smelled a electrical burn smell in the car. I cannot seem to figure out the source. That was when the window's and sunroof stopped functioning. Found fuse 43 burned out.
I have done the following:

1) Bought a used GM IV Module before I found fuse 43 blown. Tested both modules when i identified that fuse 43 was blown.
1) tested both visor for connectivity to the vanity bulbs and through the visor connector to clip. (Good)
2) tested visor against ground, no connectivity (good - no short)
3) tested visor bulb sockets to ground, no connectivity (good - no short)
4) pulled out all bulbs for map and vanity to see if the bulbs were the issue
5) let everything dangle to see if there is a short to the frame (both visors, center light, both vanity lights).
6) Checked trunk wiring by cutting open the insulation. Wires all look good.
7) Checked fuse area. Continuity when power is off shows both connections are grounded. When car has been started. Fuse 43 shows 12.20 volts. Outside fuse connector (facing front of vehicle - connects to ground). Inside shows 12v using vehicle ground and outside fuse connector).


Do not want to put my meter across the fuse to read the amps. Concerned it might damage it if the amperage is greater than 10 amps.
What else can I do?

[AJLM34A]

http://wedophones.com/Manuals/BMW/19...g%20Manual.pdf

Fuse 43 shows to be a 5 amp.

[ctung]

It keeps blowing the 5 amp fuse no matter what I try. Cannot find where the short is located.

[AJLM34A]

The c-pillar lights are also on that circuit, have you taken anything apart in the interior lately?

[ctung]

I did not take anything apart. I was driving home from work one day when I smelled that electronic burning or plastic burning smell. Then when I tested the window's they had stopped working. The c-pillar lights is the one above the rear view mirror? The two map lights do not work so I had removed them and left the center light which is working with the blown fuse. I did pull it out and let it dangle by the wires to see if it was shorting out against the car body.

[AJLM34A]

Go to the link I posted, go to group 6330.3
It has several pages that show what fuse 43 supplies power to.
.5 is the size of the wire, vi/ws = violet and white color
Page 6330.3-01, on the right side shows the splice for the rear lights

The rear lights, since they could have come apart and something could be touching the metal of the c-pillar or the ground wire for the light.

[ctung]

I cannot figure out how the dotted line works between the fuses in the diagram. IT does help show the dependency of the lights from fuse 33 to fuse 43. It also lets me know why some lights work and do not work. Some go through the ZKE and other's do not. The map lights and vanity do not work but the dome and rear lights work. All the tail lights work so I would assume that there was no short but I guess if somehow the fuse 33 circuit is feeding into the fuse 43 circuit, we would not be able to tell. I did find one of the break leads broken. I used a meter to do continuity and they seem to be separated. I did pull the break lights out but not all the lights. Tried to disconnect the connector without success for further diagnostics.

I seem to have spent a lot of time and fuses to figure it out. Maybe to check if it is the tail light section, I could pull the power cable bundle. Sooo frustrating!

[ctung]

I figured out something new today. I unplugged the cable connectors for the tail lights on both sides. The fuse does not blow anymore and the power windows and sunroof works. I did notice that the vanity and map lights are still not working. If I plug in either tail light cable, it blows the fuse. Any ideas what is causing the short?

I was reading that the cables all go into a break light switch. I read from another post that it can blow fuse when it goes bad. Do not know if it would blow that fuse.

To update anyone reading this post. Disconnecting the break light switch did not help. The fuse still blows with the tail light and the switch disconnected. It just seems to take longer (I can roll up the windows up and down many times before the fuse blows as oppose to instant). I wonder if it is a bad controller.

[NATIALE]

Thanks for the help guys, think while replacing the two map light bulbs,
all 4 power windows stopped working, the 43 fuse was blown.

[sdgusman]

9 years after this post....it still applies. Vanity mirror on drivers side blowing fuse 43. Tape everything up and keeping metal contact away from the roof.

Thanks to THECAINES

[brunp]

9 years after this post....it still applies. Vanity mirror on drivers side blowing fuse 43. Tape everything up and keeping metal contact away from the roof.

Thanks to THECAINES

Seems like this is my issue now considering that I had my headliner replaced. I do remember this happening shortly after my son started opening/closing the mirror and opening/closing the vanity mirror.

Will have to see how things look once I have daylight in my favour in the next couple of days.

Paul

[brunp]

Thank you @THECAINES

One of the vanity lights was in contact with the roof. I was able to isolate by pulling both out and swapping fuse and seeing the lights were on and then turned off the minute I pushed the light back in to the headliner. I added some think foam tape to the metal roof and now it is working again. All windows open too.

So odd to have the vanity light circuit/fuse also provide control for the windows. You'd think the circuit would be independent.

Paul