Dash lights on strike
 

Was testing out my stereo installation when I found out the hard way that the left rear - speaker wire on the wiring harness I used was incorrectly plugged into the illumination socket. I heard a faint pop when I turned on the headlights and the dash lights went out. Checked the fuse (F37), but it was intact. Is there a fusible link somewhere that I should look for, or is there something else?

nope, you blew the headlight switch. Actually you blew the dimmer part of the switch. It just happened to me a couple months ago. I bet none of the lights on your dimmer circuit illuminate(window switches, HVAC panel, gauges, doorlock switch and cigarette lighter) but the headlights, parking lights turnsignals and tailights still work right? Fortunately I have a spare. I had two spares as it would appear this is a common problem for our cars since the junkyard sent me 2 bad ones in a row and a completely different one as well. I fixed my original as well as the two bad ones that the junkyard sent me and I just sold one of the spares 3 days ago to member "cg318ti" for 20 bucks. LMK if you need a switch and we could work something out.

Yep, it's happening just as you say, headlights and all are all functional, just the dash and controls lights that are out. I was trying to pull the dash out because I figured the switch might be involved because that is the general direction that the pop sound came from but that dash just refuses to come out and I may have to resort to Astrolite if it's going to be stubborn like that. But it looks like I will need that switch, so pm me with the details. Thanks!

PM sent

Oh if you're having trouble getting the old switch out, just unscrew the knob from the switch, pry the little faceplate off of the dash with a screwdriver. Then you could either go from under the dash by removing the knee panel and support but it's really tight and you'll have to unclip the switch which could be very difficult. Otherwise, the easier method would be to remove the trim surrounding the cluster and then slide the cluster out. It's held in with torx screws, one behind the headlight switch faceplate, one behind the foglight switch faceplate and a couple more on the inner topside of the cluster trim. Once you get that panel off, you'll have easy access to the headlight switch to disconnect the plug and unclip it from the trim panel. Hope that helps.

Jesse

how about a write up on how to fix the switch? :biggrin:

Now thats asking for too much:tongue:

J/K, he's sending me his old switch and I'll be happy to do a writeup once I get it. It's kind of an involved procedure, like most of the delicate projects that I seem to fancy, but I'll definitely put together a DIY to help everyone save money. The dealer wants 40 bucks for a new switch and has to order them from Germany. The junkyard charged me 30 bucks and sent me two broken ones and a third that wasn't even for our cars. All three of the switches were broke in exactly the same spot and I'm certain that with my fix, it'll never blow again. The problem is that the resistor on the dimmer switch is too weak and blows before the fuse does, thus costing more money to replace a switch rather than replacing a fuse. It appears to be a design flaw, but like many things, can be made to work better.

More likely it was a design decision. At the time, BMW was still installing some controls that weren't protected against overloads and short circuits. They were likely aware of the limits of the rheostat they used but probably decided a short or overload in that circuit was going to be rare. I suspect they had not anticipated some of the wear and tear the wiring would experience, from normal use, repairs and retrofits.

BTW, the fuse you are thinking about is there to protect the wiring, not the consumers that are connected to it, such as the rheostat.

couldn't you just put a bigger fuse in?

You'ld actually need to run a LOWER amp fuse if you wanted to protect the dimmer rheostat from blowing due to overload. The idea would be to make the fuse weaker so that it would blow before the switch. However, since most of the fuses protect multiple circuits, you'ld be compromising the integrity of the other components installed on those circuits. The instrument illumination circuit utilizes 3 or 4 fuses which are all linked to other components. That's why if you blow a fuse from a short in your window switch, other components are likely to stop working as well. John Firestone was correct in that the fuses are designed to protect the wiring and not the actual components. Components can easily be replaced, but if by chance one or more of the wires for those components melted and shorted out, you'll be chasing your tail and scratching your head trying to find the problem. Once ran and secured into place, the wires are meant to be left alone and untouched for the entire life of the vehicle. They get brittle and can easily be damaged if they're moved, pulled or rough handled. In most cases the wires are routed through really tight spaces that cannot be accessed without tearing apart the vehicle. So I wouldn't advise changing the value of a fuse for the simple reason that you'ld be risking damaging other components or even worse the wires themselves.

can your foglight switch blowout too?

yeah, that's what I meant to say

I think anything will blowout if it gets enough voltage

well how the hell does that happen, does it mean that its a blown switch if the symbol doesnt come up on the dash when i try to turn them on

if your foglights come on when you turn on the switch but the light on the dash doesn't, it might just be that the light is burned out, but if you flip the switch and the foglights don't come on it might be a problem with the switch or the wiring