Fuse Issue

[tootz_d]

hi guys

been having a fuse issue in my S2

my interior fuse keeps on blowing out, i have replced about 5 fuse so far.

all of my interior lights work when the fuse is not blown

i've noticed that when i insert the 10A fuse it sparks

i have also tried a higher amp fuse 20A yesterday all lights working, then got into the car this morning interior lights still work started the car and went to work.

got to work no interior lights were working, during the drive i had radio on, headlights and Heater and i turned on rear dimister

has anyone had this problem?

any thoughts

cheers

[reiseva]

i had a dash lights and rear lights fuse constantly blowing. turns out it was a faulty gauge bulb. found out by in the short times when I also changed the fuse to a higher amp, the light was dull. Good luck. Im still having globe problems at the moment but hopefully fixed now.

[tootz_d]

thanx reiseva but no luck

took out the interior bulbs out but no luck

as soon as i put a fuse in it blows (wasted another 5 fuses even used a 30amp)

i tested the 1Oamp fuse for interior lights with a multimeter and it reads 16V + is that right?

should it read zero when evrything is off and the doors are close?

[QWK32]

depends on how you tested it, the interior lights are negatively switched, so the positive feed is constant. so if you test between ground and the fuse terminal you will get a voltage reading even with the lights off.

i find it strange that you are getting 16v, was that with the car running or off? should be more like ~12v with engine off and ~14v when running. and which fuse is blowing exactly, inside or outside fuse box? which row/column?

Edited May 27, 2010 by QWK32

[tootz_d]

i tested having both negative and postive one on each hole

the fuse box is behind the coin box in the inside

and the fuse is the 10A roomlamp third row, first column from the right

the car was off when i tested it

[Duncan]

ahh don't put a bigger fuse in there...it may not blow which means the wiring will melt instead.

you need to find out what circuit it is and trace it through. or drop it to a auto electrician

[andy65b]

Be careful... I had a similar problem on my M35 except the interior light kept blowing. So replaced it with a Led globe. Then the fuse blew, replaced that and sparks and smoke and net result.... semi blown Body Control Module (BCM) so a few more electronics don't work now.

I am pretty sure I have accidentally stripped the coating off a wire and it has earthed causing the blown BCM.

Work backward to when you last did some work on the car and see if you can find any marked wires.

Cheers

Andy

[QWK32]

anything else stop working when it blows, more likely to be an aftermarket accessory like cd play or gauges. i fixed up some wiring where someone installed a cd player and tapped into what they thought was a ground, turned out to be the positive line of the lighting circuit, testing the line goes back through the bulb and gives continuity to ground. had to replace most of that line as the insulation almost completely melted off.

apart from chasing the wiring and checking for shorts, i think from memory the dome light is supervised by a control module just above (or below, cant remember lol) the inside fuse box. could be a fault with that, is a white box and also controls some of the door lock mechanisms.

Edited May 27, 2010 by QWK32

[Duncan]

yeah good point about earthing throught the globe...I am at best "self taught" with auto electrics and thought that any wire with continuity to earth must be an earth, I didn't realise things like globes and probably others will show some earth continuity when the circuit is off.