Help, Electrics nghtmare..

[Barney Paull-Edwards]

Help fellers, got back from sea to the following saga.
Being lazy got garage to change rear pads,when they tried to return car the drivers window stuck open,they stopped to fix and engine would not start.jumped from pos terminal to starter and away it went. Came back from Nova Scotia on friday and started fine but when I stopped, no go.
Now the wipers only work fast, central locking no go,windows no go. Battery voltage 12.8 and drop test fine. when mechanic wiggled the fuze box under the bonnet it started.Anybody got an idea what the common wire is? Tried the fuze box wiggle just now no luck......

[Ferret]

Help fellers, got back from sea to the following saga.
Being lazy got garage to change rear pads,when they tried to return car the drivers window stuck open,they stopped to fix and engine would not start.jumped from pos terminal to starter and away it went. Came back from Nova Scotia on friday and started fine but when I stopped, no go.
Now the wipers only work fast, central locking no go,windows no go. Battery voltage 12.8 and drop test fine. when mechanic wiggled the fuze box under the bonnet it started.Anybody got an idea what the common wire is? Tried the fuze box wiggle just now no luck......

Mouse attack?

Have you tried shifting stuff around under the rear seat as well as the engine bay fusebox?

Could be your ignition barrell (sp?) is shot, it causes some weird crap to happen if certain lines are shorted/open circuit... other than that it could be one of your relays in the fusebox doing the post-office shuffle and going on strike, or it could be one of your fuses is partially blown.

However, I think it's likely that one of the bus inputs may be on its way out, if you're getting things back wiggling the fusebox.

I never managed to get my TDS fusebox out, it's a physical nightmare :/ sorry I cant be much help with that mate!

[Barney Paull-Edwards]

Thanks Andy,for the over 21`s, what is a bus input and where does it come from? just went out and nothing happens anymorew when I waggle anything, bugger!

[Ferret]

Thanks Andy,for the over 21`s, what is a bus input and where does it come from? just went out and nothing happens anymorew when I waggle anything, bugger!

Bus input is one of the main +12v power inputs to the fusebox - have you got a multimeter handy? It's likely to be the thickest red wire under all the fuses.

If so, pull the odd fuse and see if you have +12v on at least one side of each of the fuse sockets... or whether you've got something like +2v. Gimme a minute and I'll see if I can look up which relay controls the power to these lines.

[Barney Paull-Edwards]

standing by with a multi-meter, anything to Avoid Harry Potter!

[Ferret]

standing by with a multi-meter, anything to Avoid Harry Potter!

Have a look at fuses 17, 30, 31 at first, there should be some voltage on either side of the fuse sockets... put the negative/black terminal on the bodywork and probe each side of the fuse socket with the positive multimeter terminal... still looking at the moment.

Edit: 30 & 31 hide under the rear seats

[Tiger]

Fusible link by the battery?

[Barney Paull-Edwards]

Thanks Tiger but can you confirm there is only one????

[Tiger]

http://www.bmwe34.net/Wiki/tiki-index.php?page=Electrical

http://www.bmwe34.net/Wiki/tiki-index.php?page=Fusible+link

There is two of them... second one... go all the way down. Sounds exactly like your problem.

[Ross]

fusible Link By The Battery?
X2

[Ferret]

http://www.bmwe34.net/Wiki/tiki-index.php?page=Electrical

http://www.bmwe34.net/Wiki/tiki-index.php?page=Fusible+link

There is two of them... second one... go all the way down. Sounds exactly like your problem.

The diesel has a third as well in the E-box, good catch Tiger - I think you're probably right here.

http://i11.photobucket.com/albums/a190/Ferret101/Car/IMG_8182.jpg

You can just see it here, the metal link between the two phillips screws (hiding under the thick red wire.)

[Barney Paull-Edwards]

Right. Figgured a test to see if ANY fusable links have gone is to by-pass all by connecting jump lead from battery to jump-start terminal under bonnet.No result BUT when I came back to car this morning all worked fine, turmed it off, closed house, got back into car and nothing worked..........bugger. Still got fast wipers only,no start, dash full of lights,no central locking, no windows. Anybody know which relay/connection might be at fault?????Driving a `64 volvo at the moment and I cant last much longer before I kill it...!

[Tiger]

Barney, I really don't know how you really can bypass any fusible link in the method you were talking about. Did you even test the fusible link by removing it?

[Barney Paull-Edwards]

I ran a jump lead from battery to terminal under bonnet which has a lead direct to starter. surely this bypasses any interruptions in the positive side of the system?

[Tiger]

Using battery jumper cable? I don't think it does because on E34 there are two fuse boxes where there is two direct battery positive cable goes there... and one monster positive cable goes to starter and alternator.

You are thinking of ground path... which doesn't care which path it takes. Positive side does care which way it goes and has a strict path.

You could have a ground issue but then again, if you don't do the process of elimination, then you will never get it done.

[Barney Paull-Edwards]

I traced the main lead, the thick one, and it ends up on the exposed terminal under the bonnet. The Fusable links on mine are a bastard to get at,but did not know about the third one in the other box, will investigate that in daylight but just confirm that my method of eliminating the other two works?

[Ferret]

I traced the main lead, the thick one, and it ends up on the exposed terminal under the bonnet. The Fusable links on mine are a bastard to get at,but did not know about the third one in the other box, will investigate that in daylight but just confirm that my method of eliminating the other two works?

Barney mate, I dont think this will eliminate the two fusible links - there arent any fusible links on the actual thick starter cable - they'd explode every time you tried to start the car.

They're on the smaller wire that comes off the battery - there's a .75 cm thick red cable that branches off the battery positive terminal as well - I think that's the cable this is on.


However, you may have found something - by jumping to the positive point you've made the car operate for a short period - try taking apart that positive post - there should be some fuse box supply cabling anchored to it... (I think) it's a distribution point. Before you do, take a voltage reading off the jump start post and see what it reads compared to the battery.

If you take it apart, dont forget to unplug the battery like I did!

[Barney Paull-Edwards]

Nearly a week later! Tried both findable fusable links, the one by the battery and the one in the ECU box, both ok. still got same symptoms,any other ideas???

[632 Regal]

bypass the fusable links 1 at a time, I also believe this is the problem. Fusable links are intermittant and can check out good but really they are hiding their faults. usually they can crack on the inside and you will never guess they are bad. This is my guess.


Nearly a week later! Tried both findable fusable links, the one by the battery and the one in the ECU box, both ok. still got same symptoms,any other ideas???

[Barney Paull-Edwards]

Have 12.8 volts all down the line,fuse in ECU box has volts both sides and looks perfect, link near battery looks the same and has power both sides. Now going to try to find fuse 37(!) after that ??????????? Assume that UK diesels have no underbonnet link as battery under seat,cannot find one there, make sense??

[Ferret]

Have 12.8 volts all down the line,fuse in ECU box has volts both sides and looks perfect, link near battery looks the same and has power both sides. Now going to try to find fuse 37(!) after that ??????????? Assume that UK diesels have no underbonnet link as battery under seat,cannot find one there, make sense??

Yeah, from what I remember, the diesels 'second' fusible link is that one in the e-box now I think about it. I'd definitely try using something to jump across the fusible links - especially the one near the battery

For peace of mind, the next thing I'd check is the back of the ignition switch with your multimeter - check that you're getting voltage actually sent to the fusebox.

Might be able to come lend a hand on sunday if you're around and still stuck

[Barney Paull-Edwards]

Thanks Andy, may call/txt if still stuck,costs will be met! Attacking the switch now.

[Ross]

On US petrol cars the main battery cable comes through the firewall around the e-box. There is a terminal block there with several hot leads. Perhaps a loose or corroded connection there. ALSO the main cable has a "T" in it just inside the firewall, one side goes to said junction block, the other to the ign. switch as I recall. It would seem an unlikely failure but just so you know there is a joint there.

[Barney Paull-Edwards]

Thanks Ross, but do you mean the main battery cable or the Red main feed wire? The branch you mention, is it in the passenger compartment or the engine bay? If it goes to the ignition switch I assume it is the main feed wire.......

[Ross]

Thanks Ross, but do you mean the main battery cable or the Red main feed wire? The branch you mention, is it in the passenger compartment or the engine bay? If it goes to the ignition switch I assume it is the main feed wire.......
Main battery cable on our cars with the battery beneath the rear seat.
The branch is just inside the firewall I remember, behind the glove box. Not sure how all that goes in RHD cars.
#2 here, http://www.realoem.com/bmw/showparts.do?model=HE13&mospid=47406&btnr=12_0482&hg=12&fg=29

the junction is actually a tee covered in black plastic, one heavy cable in, one heavy one smaller out.

[Ferret]

Main battery cable on our cars with the battery beneath the rear seat.
The branch is just inside the firewall I remember, behind the glove box. Not sure how all that goes in RHD cars.
#2 here, http://www.realoem.com/bmw/showparts.do?model=HE13&mospid=47406&btnr=12_0482&hg=12&fg=29

the junction is actually a tee covered in black plastic, one heavy cable in, one heavy one smaller out.

I'd also check the jump terminal, post #9 - dismantle and clean this up just in case.