indicator fuse keeps blowing

Tue Apr 24, 2007 3:32 pm

Hi all,

A strange occurence last night. I was driving home and suddenly (on the last turning before getting home), I flicked the indicator on and heard a click, but neither indicator was working.

So I did the obvious thing and had a look at fuse no 4 (15A), and it had blown. I changed the fuse and the replacement just popped in my hand, as soon as I put it in the fuse box. I've now blown 3 fuses in there, and obviously, this means I've got no indicators. The hazards work fine though.

So what might be causing this? A dodgy earth? I'm no electrician, but I guess that's logical? No idea what may have caused it, was working fine until 2 mins before I got home.

I've seen some posts mentioning the glove box lamp, I guess I'd better check this? My car's a 1990 320i.

All help appreciated, and I bet Brian shares his wisdom on this one!

Cheers all.

Tue Apr 24, 2007 4:19 pm

BUMP!! I need to sort this tonight, or the mrs will kill me!!

Please help!

Tue Apr 24, 2007 4:41 pm

the first thing to answer is does the fuse blow if the indicators are on or does it just blow when you put the fuse in (without indicators on?)

I will assume for the rest it does not blow with the indicators off:

2nd does it blow on right or left indicators or both?

3rd does it blow when you turn on the hazard lights? do all the bulbs light up?

4th with ignition off, do your parking lights work (left and right)

note a dodgy earth will not cause a fuse to blow, rather it will cause the lights not to work, what caues a fuse to blow is normally a dodgy ''live'' as it touches ''earth'' it creates a short circuit thus high current and the fuse blows to prevent an electrical fire or more serious damage.

Tue Apr 24, 2007 4:45 pm

oh by the way, glove box light is not connected with indicator circuit to my knowledge thats fuse 21, which is only linked to indicators through the check panel

Tue Apr 24, 2007 4:52 pm

Hi Mrlee,

Thanks for the info, makes sense what you say about the live earthing itself, I did say I'm no electrician! I hate electrics in fact, but needs must!

Anyway, in answer to your first question - the fuse blows as soon as i put it in, regardless of the indicators being on. So yes, it does blow without the indicators on. Amazing how much a little spark can make you jump!

The hazards still work, even with the blown indicator fuse, so I'd guess it can't be the hazard switch, which I've heard can cause a problem. No idea about the parking lights, I know the headlights work though.

So, who's got any (bright!) ideas?!!

Sorry about that, what a poor joke!

Tue Apr 24, 2007 6:11 pm

it seems like you definatley have a short somewhere, check the front or the rear of the car's indicator lights connections, the positive wire maybe touching the body of the car somewere.
i had that problem once, but it was because of the water in my rear cracked lamp
ps: if no electrical improvisations were made on the car recently you should first check the wires near the indicator lamps

Tue Apr 24, 2007 7:14 pm

In spite of what the BMW handbook and mrLee says, the glovebox light on your car is connected to the indicator fuse, and the glovebox light is almost certainly the cause of your problem!
It's unlikely to be anything to with any of the indicator lights or their wiring, because a) The fuse blows with the indicators off, and b) the hazards fuse would blow as well!

Tue Apr 24, 2007 7:38 pm

hi brian, I thought as much! I'd seen some other posts but wasn't sure where the best place to start would be, had seen that the glovebox light was connected to the indicators. I think you've contributed to every post I've made here, a true legend, thanks!

I'll go and check the glovebox, it's in a bit of a mess since some little *#!$* broke in and tried to nick the radio, but the problem only materialised the other day, and they got in months ago. I'll check for a short on the light and hope to get a quick result this time!

Cheers

Tue Apr 24, 2007 7:48 pm

Glove box lamp holder can short circuit if it doesn't have a bulb in it. Make sure the brown wire on it is connected to the lowest terminal (as the switch sits in the car).

Tue Apr 24, 2007 7:55 pm

thanks, i'll go have a butchers, although I've blown all the 15A fuses I had!

I'll figure something out ....

Wed Apr 25, 2007 9:31 am

In spite of what the BMW handbook and mrLee says

well thats what i learnt today!! but i was only going off the drawings in Bentleys in my defence your honour!!

worth also noting that the clock seems to be on the fuse 4 circuit, so if its not your glovebox light then check the theiving little cnuts didn't knacker the wireing round you clock supply as it is close to the radio and could be touching the body somewhere.

good luck

mrlee

Wed Apr 25, 2007 9:39 am

mrLEE30 wrote:
In spite of what the BMW handbook and mrLee says
well thats what i learnt today!! but i was only going off the drawings in Bentleys in my defence your honour!!

Changed in about mid '88, but the handbook wasn't updated, nor the colour of the wire to the light.

Wed Apr 25, 2007 10:25 am

well there you go! learnt two things today, means i can get drunk tonight and not have to worry bout learnin stuff tomorrow

mrlee

Wed Apr 25, 2007 2:50 pm

good plan that mrlee, I'll have a look at the clock. They've wrecked the plastic surround, and the clock is loose, but wires seem to be ok. Strange if it was that, as it's been like that for a few months now.

My radio's also knackered, no power at all, but that wasn't caused by the thieving little sods, that was my "mate" trying to fit a new aerial for me! I'll save that puzzle for another day, otherwise I'll get really confused!!

Thanks all, now I've just got to wait to finish work before I can go and get it sorted! And I didn't manage it last night, there were a few too many pints with my name on them...!

Thu Apr 26, 2007 12:05 am

i had the same problem and it turned out to be the rear light cluster, the metal contact to the body of the car was not connecting and i assume not grounding the circut ......

Sat May 05, 2007 11:50 pm

did you ever find an answer to this problem????

Mon May 07, 2007 2:16 pm

Hi DAG - did find the answer to this problem, and it was the glove box light. As mine doesn't have much glove box to sit the switch in, due to some little bas*#rds breaking in, I couldn't put it in properly, so just taped the two wires up that lead to the lamp, and that's completely solved it. The two wires were shorting together.

Hope that helps!