Electric Window & Cig lighter fault

[soul4t]

Hi,

I had a problem with my 1990 e30 316i, the passanger side window started to blow the number 17 fuse (30amp). I also noticed that the cigarette lighter socket was at a lower voltage (I had a multi cigi lighter thing that had a voltage light indicator) the windows would no longer work when the doors were open.

I decided to sort it out today and checked the fuse list, which indicated that the fuse number 28 runs the cigarette lighter and the window circuit when the doors are open. I checked it and it had blown. I didn't think that this would fix the problem and to be fair it still might not, but I replaced this fuse and the passenger side window no longer blows the number 17 fuse and the windows now go up when the doors are open!

I'll obviously re-post if anything blows again as it's not had sufficient test unless it's been tried with other electrics. I suppose it may have blown if the cigrette lighter circuit was overloaded/short circuited somehow?

Either way I thought I should post this up here in case anyone else has the same problem!

[Brianmoooore]

If fuse 17 was blowing when you operated the switch for the passenger window, then the same fault will blow the cigarette lighter fuse, 28, if the passenger window switch is operated with a front door open.
The problem appears to be an intermittent one which has temporarily cleared, but the chances are it will return. The fault can be anywhere between, and including, the switch and the window motor, and the first place I'd look is for something metallic (aluminium foil, pin, paper clip, etc.) that has found its way inside the switch.

[soul4t]

Hi Brianmoooore!

Thanks, I'll have a look when I get the chance.

Thanks for your input!

[soul4t]

Brianmoooore was right,

Interestingly the fuse I put in temporarily to replace the 25A fuse in slot 28 was a 30A fuse. When I put the TomTom into the Cigarette lighter, and used the window it blew fuse 17. Fuse 28 was fine. The windows work fine when one of the doors is open, then after a couple of days fuse 28 went. I'll be investigating during this week and will post my findings!

Thanks for your input Brian, presumably!

T

[soul4t]

Right, update!

I removed all the center covers around the switches and handbrake, checked the switches for any signs of damage/fault, also checked the window lift circuit breaker, also the cigarette lighter, no signs of shorting or any foreign parts stuck in them.

I'd like to add at this point that the fuse which blew in slot 28 now glows! Yes glows! when either door is open, so when the circuit is operated. So what appears to have happened, is too much amperage is going through the circuit protected by fuse 28, (possibly a short circuit?) over the period of a day when it appeared to be working, each time the doors were open, it started to melt the fuse innards, then when it broke the connection it seems to have melted the innards into some strange connection (within the fuse) which is hot enough to glow when the circuit is open.

I looked at the passenger side door at the motor, there appeared to be a slight burn on the protective plastic which lies next to the window motor, so I unplugged the window motor and re connected the battery, the glow was still there! So presumably this removes the motor itself from the equation, I also swapped the switches, same glow. I have thought that it could be the circuit breaker? But I'm not 100% sure how to test it? Would I just bridge the connections? So my next part to check will be the wires which go from the door into the main car compartment.

Any advice Brianmoooore? Or indeed anyone else?

Thanks!

[Brianmoooore]

Does the fuse glow with the doors open, and without touching either window switch?
Do the windows work at all, with the door open and/or closed?

[soul4t]

Thanks Brianmoooore!

Yes the fuse glows with the doors open, without touching either window switch. If I put a new fuse in slot 28, both windows work with the doors open, without engine running or key in ignition (as they should I believe), but then I remove the new fuse as I don't have many left! So the old glower is in there. Currently, (with a good fuse in slot 17 and the broken glower in slot 28) I only operate the drivers side window, which will only work when the key is at position 2 or engine running, nothing works with the doors open as it stands, presumably because the circuit is broken at the fuse box...but then why the glow? Some current must be going to one side if the fuse, and the other grounding? Should I remove the fuse for now?

Thanks mate!

[Brianmoooore]

Something very strange and potentially dangerous going on here!
Did this fault suddenly develop, or did you inherit it when you acquired the car?
The sunroof (if you have an electric one) is also supplied from the same source, so the first thing to do would be to disconnect one of the green/blue wires at the relay behind the glovebox, to establish which loom the problem is with.

[soul4t]

Thanks Brianmoooore,

Yea, the fault just appeared, about a week after driving back from france, I took it on a short trip before I had to sorn the car for a couple of months, on the way to my destination on the short trip, fuse 17 blew. I hurriedly (when pulled over) flicked to the fuses section of the Haynes manual and checked fuse 17, replaced it and put the windows up, then when I used the windows again it blew again, bought some new fuses and started trying to isolate it, but the car was not being driven for a little while so I didn't fully investigate. Car back on road in June. Only since looking for the problem now, have I found out about fuse 28.

I don't have the electric sunroof so thats good! I'll look for the relay behind the glovebox and try to find the circuit that is at fault.

I did check a relay in the main relay box (LHS near the diag port) for any signs of charring, which might indicate a problem, do you think it might have anything to do with that? Any better way to look/check for relay fault?

I'll keep you posted!

Thanks again!

[soul4t]

Hi,

Right, I've done some investigaion this evening...

I took the glovebox down and had a look at the wires by the relay.

I disconnected the green and blue wire, then looked to see if the glow would continue, it did.
I disconnected the black and white wire and checked the glow...still aglow.
I disconnected the red and yellow wire and there was no glow, but I believe that is the power to the windows as it didn't work the RHS window, even with the ignition on.
I removed the relay, the outer pins looked slightly charred, could this be at fault?

I should add at this point that that sometimes over the last year we've used a multi plug in the cigarette lighter to run a fridge while travelling and phone chargers and tom tom. I thought at this point that surely this points to the cigarette wiring as it's protected with fuse 28 along with the window circuit with the doors open.

So I removed each wire from the cigarette plug individualy and the glow was still there!

I didn't have much time to investigate further.

Does this point to anything and is there anything that I should be focusing on next?

Thanks for any input!

[Brianmoooore]

Green/blue wire is the feed out from the relay to the windows.
White/black is the power into the relay from fuse 17, and is only live when the ignition switch is fully on.
Red/yellow is the power into the relay from fuse 28, and is live at all times. Fuse 28 also feeds the cigar lighter and the electric aerial (if you have one).

What colour is the relay case?

[soul4t]

Wow!

Amazing concise information!

The relay case is blue.

I have an electric aerial, the part which comes out of the car is not a good fit, should I try unplugging that as it could have got a bit damp in there?

The aerial works fine though.

Thanks for your help!

I've been having a look at the info on wiki about the looms, but I can't seem to get as concise information as from you! Thanks soo much!

[Brianmoooore]

The relay case is blue.

Pity! That's another theory gone West - I was hoping someone had fitted the wrong type of relay.
So: Fuse glows when red/yellow is connected to the relay, but not when the red/yellow is disconnected from the relay?

Red/yellow connected, green/blue and white/black disconnected it still glows?

What if the red/yellow is connected and the brown/blue disconnected?

[soul4t]

Hi,

Just re-checked the above and yep fuse glows when red/yellow is connected but doesn't glow when red/yellow is disconnected.
When both or each of the green/blue and black/white connected or disconnected, still glows

I'm going to have another look, but I can't find a brown blue one? I have a light green one? There is also another green/blue one that isn't connected...would this be for a car with 2 rear doors with electric windows?

I have just noticed...if it makes any difference, that the fuse glows and fades steadilly after the negative from the battery is disconnected...if that helps...like a capacitor discharge?

Thanks again for all the help!

[soul4t]

Ahh the Brown blue wire...found!

It went from the back of the relay, to behind the speaker, where I believe it connected to the door sensor?

I unplugged it and the fuse still glows!

Whilst looking for the wire I went into the door again, I unplugged the window motor and still the fuse glows!

So, so far, the only things which stop the glow are the obvious, removing the relay, or taking the live feed from fuse 28!

I can't see where the live feed goes to the aerial, I think it must go a different route from fuse 28 (which would make sense), the red/yellow wire coming out of the accessory socket has a branch out bit (presumably for electric sunroof if fitted?) goes to the relay only. There is a yellow/brown wire bridging the relay from top to bottom.

I'm going to have a think!

P.S, I don't know if I'm accurate in saying this, but the wiki page on loom mentions that the Antenna is powered from slot z on the accessory socket, but it doesn't seem to be on mine, on mine it's the red/yellow wire that I've been discussing above...I'm not sure if it's the same for all models?

[soul4t]

Ok,

Weird!

I've just been trying to find out what might be happening using a multimeter...hmm, a definite learn for me. I notice that with the doors open, fuse 28 recieves 12v or thereabouts, so something is drawing current? (I know current is measured in amps, my multimeter won't permit anything above 10A but if nothings drawing current, you wouldn't get any voltage reading either right?) Which we know anyway because of the glow...but when I check fuse 17 when the window switch is operated and the key fully on, nothing?

Anyway, thats not the weird part as it's probably down to my understanding...what is weird is that I unplugged what I thought was the door sensor...with it unplugged and the drivers door open, if i shut the passenger side door, the glow stops!!! If I reconnect the wire and shut the passenger side door leaving the drivers side open the glow stays! Have I just unplugged the drivers side door sensor?

I know I'm blableing a bit here, but I just wanted to document what's going on!

[soul4t]

Just to confirm, I unplugged the wire from the actual sensor on the passenger door side and the other thing that I unplugged must have been the drivers side. With both unplugged, no glow.

[soul4t]

Right,

Just a quick update...

I've removed the glowing fuse 28, for now, I've kept it for testing.

I was driving a mate around and forgot to tell him about the window, he lowered it and I assumed that it would have blown, or would blow when it went up....it didn't!

When I got home again I tried different combinations of with window switches, like doing them both at the same time and doing them when the window was fully up etc, and with the door open...couldn't get it to blow! So I wonder if fuse 17 was blowing in an area that is connected to fuse 28...I'll keep you posted!

Brianmoooore, do you by any chance have the wiring diagrams and or loom wiring diagrams for my year car as the one's on the wiki pages don't quite seem to match?

Thanks!

[Brianmoooore]

..what is weird is that I unplugged what I thought was the door sensor...with it unplugged and the drivers door open, if i shut the passenger side door, the glow stops!!! If I reconnect the wire and shut the passenger side door leaving the drivers side open the glow stays!

This seems to suggest that the rogue current path is just the normal one that should flow through the coil of the relay when a front door is open, but or some reason is many times greater than it should be.
The only possible reason I can think of for this is that your relay has developed multiple shorted turns in its coil.
Remove the relay, connect pin 85 to the positive side of a 12 volt battery, connect 86 to the red lead of your meter on the 10A current range, and touch the black lead of your meter onto the battery negative pole.
The relay should click, and you should get a reading on your meter.

[soul4t]

Hi Willnz, Thanks for the link, those diag's look usefull, but don't seem to have all the info I need...thanks though!

Hi Brianmoooore!

I'll do that test and let you know how I got on!

Are the circuits wired via the fuse to the full power of the battery, with the fuse rated at the maximum normal current that might be drawn from that circuit (in the circuit protected by fuse 17, the power windows)? I'd appreciate if you would humor me!

Thanks guys!

[Brianmoooore]

Will's link is to the circuits I normally use, but these are to US spec., and there are several differences between these and UK cars.
One of the differences is that the whole relay circuit under discussion here is missing, and on US spec. cars the blue/green is plugged into the accessories socket, where the white/black is on UK cars.
The fuse ratings are chosen to protect the wiring - the motors themselves are protected by the resettable cut out in front of the RH window switches.
There's no limit switching on the window motors, so when they hit the stops the motor just stalls and the current drawn increases dramatically. Under these conditions the resettable cut out should trip before the stalled motor heats up enough to damage itself.

[soul4t]

Ahh I see!

Thanks for the explination!

I'll keep you posted!

[Sesq]

I have aqquired a 318i Touring which also likes to lunch no17 and no28 fuses. Front windows behave as they should (manual rears & sunroof) but popped both a pair of replacement fuses in a matter of hours today.

I found a broken red wire in the flexi section between door pillar and door, where the look passes through. It's a right old bitch to get at it, though.

[Brianmoooore]

Do the fuses pop when the window switches aren't being touched?
Red wire is nothing to do with this if it's an original BMW wire, and not part of some bodged repair.

[Sesq]

I'll have to replace them and see but it's SORN at the moment so isn't in active use. I understand the wiring diagrams that deal with ignition on/doors closed but where in the diagrams would I find the circuits that deal with ignition off/doors open ?

[soul4t]

Hi Brianmoooore and Sesq

I've been busy of late, so I've not spent much time on it, but I'll be back on it on Wednesday!

I realised that I actually managed to blow my multimeter's 10A setting a few months back so I thought I'd see how much a replacement relay from BMW was, it is only £8.97 + vat, not bad at all! I thought I may as well try this instead of paying a little more for another multimeter.

Soon after my last post, fuse 17 blew and glowed...embarrasingly enough, I have now realised that the glow is in fact an LED on these fuses which lights up when the fuse if blown another embarassing discovery! I have gone through a couple more fuses in 17, they seem to be going quicker of late...

I should get the replacement relay in on Wednesday..I'll keep you posted!

[Brianmoooore]

.embarrasingly enough, I have now realised that the glow is in fact an LED on these fuses which lights up when the fuse if blown

A new relay won't fix the problem.

[Brianmoooore]

but where in the diagrams would I find the circuits that deal with ignition off/doors open ?

All the online diagrams seem to be for US spec. cars, which don't have this feature. I've never seen this part of the circuit in print.
The same goes for the UK foglight circuits and touring rear wash/wipe.

[Sesq]

Turns out no28 fuse is intact and the windows operate under those circumstances ie; doors open ignition off.

I've ordered a power probe and a little circuit breaker and have started pulling out trim round the p/window loom. LOL Joy.

[soul4t]

I'm getting a new multimeter today and can start retesting...weather permitting!

Sesq, Thats good, my fuses didn't always go straight away, sometimes a few uses, we should be able to check the amperage accross the fuse while the circuit is open with multimeters right?

Thats how I intend to test, then go through each element of the circuit disconnecting bits to see if they are faulty/are connected to faulty/earthed/shorted wiring.

Keep us updated on your progress!

[Sesq]

Personally I wouldn't bother checking the load on the fuse. The fact it's popping consistantly is enough to indicate an issue.

I pulled the drivers door harness today and found some evidence of chafing right near the motor plug, probably the wires rubbing against the door frame behind the trim.

This car has loads of little grmlins which I'm determined to fix so pulling the whole harness seemed like good pratice. Plus it was the easiest loom to remove to start with. Someone has done the red/black mod but left exposed wires here and there so that whole loom is getting the boot, the c/locking loom was full of water (but still worked on this door!) and I found a few bits of damaged insulation here and there. I've half a mind to replace the whole harness. Is it possibile to buy suitable wire in the same colours so as to preserve the OEM colour pallette ?

I think you may have to bite the bullet and start pulling harness' too!

edit: I think my previous Nissans spoiled me. I had an old £150 Bluebird with electric everything and a Silvia Turbo and both sets of electrics all worked perfectly.....

ninja edit: I've spotted a little box 'o' tricks in my loom behind the glovebox which is part of the main harness. Um, what is it ? MY car has front leccy windows but manual sunroof, no light wipers etc so no really snazzy options.

[soul4t]

Sesq, I agree, no doubt that there's an issue.

I tested the switches and cigar lighter circuits under different circumstances while observing the load at the fuses 17 and 28. I found that occasionly when putting the drivers side window up the load increased beyond 20A, (shows "1" on the display) when normally it is put up load doesn't exceed 8A. I swapped the switches round when I took most of the circuit up to test before, and before I swapped them it only blew the when using the passenger side window.
So I took the switch apart and saw that the "up" button of the switch had a part of the contact out of place, it looked like it may have been contacting part of the led circuit part of the switch assembly. So I cleaned it all up with contact cleaner, then rectified the contact that had come out of place.

All is back together, I tried the windows a few times to make them blow and they didn't, so hopefully that was it!

Fingers crossed!

[Sesq]

I haven't checked the switches yet. I repaired the moody looking insulation on the drivers door but it didn't stop the fuse blowing. After some to'ing and from'ing I removed no28 fuse and the alarm cheeped at me.

With no28 fuse removed, but no7 insitu, I have no driver's door activity but the passenger door window works fine, so long as both the ignition is on and the door is open.

So I decides to remove the moody alarm, with it's rusty bracket and bad earths, but decided to bin the even moodier tow bar electrics first as it looks easier. That's when I find a swimming pool under the passenger carpet. Looks like water is getting in where they chopped into the rubber wather seal by the factory loom, to route the wire along the passenger side of the car, and only blocked it up with a glob of goop.

[soul4t]

Ahh No!

That doesn't sound good at all...have you been able to dry it out?

The wiring in your car definitely sounds different to mine.

This is the video I found showing how to take the switches apart. I tried to get a new switch from GSF before I tried this and they didn't have any in stock at my store and it's a discontinued line! They tracked one down from another store and had it sent to my local store, I'm going to pick it up and keep as a spare!

Just to keep this updated, my windows seem all fixed now almost a week gone and I've been using them almost every day.

Hope you can get to the bottom of your problem Sesq!