Dash Lights Blowing Fuse

[yeah_mick]

last night i was driving along and my dash lights all of a sudden went out, so i pulled over for a quick check and ive also got the rear drivers side light out, after a quick look at the fuse listing they are both running off the same fuse, but i replaced the fuse and it went again straight away. this a common problem? any idea on what could be causing it?

[Brianmoooore]

Pull the four pin radio plug out of the accessories socket at the back of the glovebox area, and see if that stops the fuse blowing.
Any chance the car has had a towbar at some time? My latest purchase has holes in the boot area where a towbar had been removed some time ago, and I found the towbar electrics cable just cut through, with no attempt to insulate the individual wires at all, tucked away in the LH stowage area!

[yeah_mick]

ill try that in the morning, my granny owned it for the last 13 years and she never had a tow bar fitted and if she got it with one on she wouldnt of had it removed.

ive been doing a bit of googleing and 2 things that keep getting thrown up is certain wire behind the stereo or the actual light switch itself. i had a play with the switch earlier and hen you turn it left to right it does feel a bit grindy and have a notch in it which is never used to have.

the plug you say to unplug? what exactly is that? is it for the radio as the name suggests? what will it do if left unplugged?

[Brianmoooore]

The headlamp switch fault causes the panel lights not to work at all. I've never known or heard of the switch being responsible for a blowing fuse.
The wiring behind the stereo is the most likely cause, but if you dive in and disturb it, the chances are that you will cure the fault without knowing what you've done, until it returns again in the future.
The art of fault finding is to stay completely away from the area the fault is probably in, until you have proved beyond reasonable doubt what the fault is. For this reason I suggested you pull the radio wiring loom at the accessories socket and see if this stops the fuse blowing. If it does, you move onto the wiring behind the radio, where you will have proved that the fault is.
Leave the plug disconnected, and, if your radio is installed properly (a big 'if'), your radio won't work.

[yeah_mick]

ok ill give that a go, im pretty sure the radi is all in properly, i used the diagram from the harness i bought and the diagram of the e30 wireing to wire it in and its been spot on for the past 9 months

[yeah_mick]

i changed the switch and all was well till i hit a bump on the motorwa and it all died again. so i guess it wasnt that, ive only just managed to get my head unit out to check all the wireing from behind there here is what i have

stereo car
orange>>>>>>>>>>grey/red
yellow>>>>>>>>>>green/red
black>>>>>>>>>>>brown
red>>>>>>>>>>>>purple/grey
blue goes to nothing

and all the other ones are speaker cable and they are all in check and working fine.

[yeah_mick]

i replaced fuse 23 with a new 7.5 amp fuse, all was going well lights all working, drove round to my mates house all fine, on the way home i was coming out of a round aabout and the car bogged down and wouldnt rev, then picked up again, then i could smell a burning smell, like frying wire and the dash was really dim, then the car bogged down and died and wouldnt start, i checked use 23, the fuse wasnt burnt out but all the plastic around it was melting, i pulled it out and swapped it again and its not blown, no burning smell and car drove home the rest of the way absolutely fine.

please help me before i cry

[Brianmoooore]

What's the orange wire for on your stereo? Is it a BMW stereo?
From what you describe, fuse 23 is being blown by an overload rather than a short circuit.

[yeah_mick]

its a sony stereo. ill have to pull it back out to check what the orange wire is. its just weird that it has been fine for 9 months, then all of a sudden its going wrong.

[yeah_mick]

left for work just after i posted my last message, 4 hours late i was home on a recovery truck, my fuel pump has died, i belive it to be completely unrelated and just a coincidence to last nights fuse melting. but im still stuck on the wireing with the stereo/lights. i dont see how it can be over loaded ive only got the same stuff ive had on there for months and never had a problem

[cragles]

Does this fuse also feed the small sidelights bulbs?

The reason I ask is that I went through about 4 7.5 amp fuses on my e30 until I started investigating. I found that one of the sidelight bulbs was damaged and therefore kept blowing the fuse. May of been fuse 22 or 23 if I recall correctly.

[yeah_mick]

accordiing to my haynes manual fuse 23(the one thats blowing) only powers the instrument cluster lights and the rear divers side light.

[cragles]

According to the wiki it runs more than that fella.

http://www.e30zone.net/e30zonewiki/inde ... se_ratings

[Brianmoooore]

Fuse 23 powers the RH tail light, the RH front parking light, both number plate lamps, radio illumination and all the instrument and switch lighting with the exception of the headlamp, foglamp, roof and window switches.

[yeah_mick]

ok, can you point me in the direction of there this stereo plug is behind the glove box? i just found a hand full of relays, if its them which one do i unplug?

from reading the wiki am i right in thinking that the rear windw demister is on there? i did have that on last night to clear the condensation off the window.

[cragles]

I know it sounds like a lot of work, but maybe remove all the bulbs listed as being used by the fuse. If it still blows then it's not a bulb, if it does not blow, start adding the blubs until it blows?

My experience (above) found it to be a faulty bulb.

[yeah_mick]

the only problem is that it will work fine for a few hours or so, last time it was fine unil i hit a bump on the m25 and the fuse went.

[cragles]

Does the fuse always blow at night ie. when you have your lights on?

[Morat]

The accessories board you're looking for is behind the glove box. You just unclip the straps that hold the glove box off the floor when open then undo the screws/clips at the top of the glovebox interior trim and there's another one about halfway down that piece on the right hand side. Once you've found all the clips you should be able to easily take that "roof" of the inside of the glovebox out and you'll see what Brian is talking about.

[yeah_mick]

1st time they went was at night, then i swapped a fuse and it went instantly, next time i was just driving along at night and the fuse went, since then ive had the stereo out and looked at the wireing and it was as i stated earlier. after that it would melt the plastic on the fuse and start to smell of burning after a minute of having the lights on, so this afternoon, i pulle the stereo back out, soldered all my joins in the wireing for the stereo and heat shrinked them all, it now takes about 10 minutes before i get the burning smell. i think im going to cry soon, how do i get out all the surround with teh heater and fan controls and stuff on to have a proper look behind there?

[Brianmoooore]

What's the orange wire for on your stereo?.

[cragles]

Does your stereo need a feed for illumination?

On a standard ISO connector, orange is for illumination, red for switched (ignition live) and yellow for battery (permenant live)

Can you disconnect the stereo and try running without it for a few days? Obviously this can be done by simply disconnecting the connector at the rear of the stereo, or otherwise disconnecting the connector behind the glovebox.

[yeah_mick]

missed that bit of your post brian, ill ill pull it out tomorrow and have a look at it, the stereo is sony unit. quite a recent model. the connector i used was from halfords, it was a iso connector that connects to the stereos loom then was just bare wires on the end which i soldered into the standard car loom, every connection is insulated in heat shrink, including the ends of the wires that arent in use.

[yeah_mick]

the orange wire is for illumination

[Brianmoooore]

Did you try running the car with the radio plug disconnected at the accessories socket?
Do the RH parking lights work OK, without blowing fuses? (The function controlled by the indicator switch).

[yeah_mick]

just got back from holiday, ill do what you said once its stopped raining and let you know. this is doing my head in now.

[yeah_mick]

fuses arent blowing though atm, they are just melting and getting realy hot

[yeah_mick]

im outside now with all my glovebox pulled out, ive unplugged that plug and the stereo wont work with it unplugged. so shall i leave it un plugged for a few days and see if the fuses blow? the wireing on the stereo all looks spot on.

[yeah_mick]

with some digging it appears i have 2 alarms fitted to the car. 1 code alarm which i have a fob for and does work but the siren has been removed, and one foxguard i dont have a fob for but the little led is flashing away on it. if anybody is familir with either of these could they drop me a pm as i may aswell remove them as they dont work and i would rather fit a decent one in there. with more digging the foxguard seems to be linked into the codealarm system as part of the shock sensor.

[yeah_mick]

with the stereo plug behind the dash unplugged i took it for a drive and it melted the fuse and started to smell of burning after 5 minutes of having the lights on. i will this afternoon pull all the bulbs on that circuit and put them back in one by one. is there anything i can test with a mutimeter to find the problem? im ok with fixing problems just trying to find them is my problem.

the plug pulled from under the glove box was 4 pins vertically near the lop left corner of a big board of plugs, that the right one? it did stop the stereo when i pulled it.

[Brianmoooore]

That's the correct plug, and it seems the radio wiring is innocent.
The wiring for the internal lights (and I think the number plate lights) can be separated from the tail/side lights at the main lighting switch, but I can't remember the exact details, and I'm 800 miles away from mywiring diagrams at the moment.

[yeah_mick]

by the main switch you mean the one you pull to turn them on?

[Brianmoooore]

Yes, although the two circuits are fed by the same fuse, they are switched seperately at the main lighting switch, and are completely separate from there on.
Have you tried leaving the parking lights on? (Using the indicator switch) This only powers up the front and rear sidelights, leaving the internal lights and number plate lights off.