E30 Zone

just putting the car back together
hooked up battery no major things seemed wrong,
flick ignition key and lights on dash come on ormal
next thing a puff of smoke and loom is badly badly toasted
it seems all positive feeds to the three relays on the turret are melted through.
spent the last 2 hours getting and replacing the loom but dont want to hook up the battery again as i have fixed/changed noithing and cant understand why it happened.

only a positive wired direct to earth would cause sucha quick bad meltdown but i dont know where i am going wrong.

can any one suggest what i did wrong.

am guessing it is to do with the small wire blsck wire that comes with the fat positive wire from the boot to the bulk head positive block. where does the small black wire go? i had it wired to the the group of red wires from the turret.

this is the only wire i dont comprehend the job off - i understandwhat the rest of the wires do i think anyway!


anyhelp gratefuly appreciated!


325i sport loom/engine/

no idea really but black shouldnt be connected to a live red. black will be to negative or car body earth. leave the black one of and see what happens.

does it not go under one of the front top mount nuts to act as an earth?

well you could be right
BUT i am wondering

The positive terminal of the terminal on the battery in the boot has the main (thumb tickness) poitive wire, and a small diameter black wire too,

then in my engine bay that thick wire ends up at the positive block, mnaybe i was stupidly presuming the small black wire coming out of the bulk head with the thick wire is the same as the one thats on the battery in the boot -

if anyone want to take a picture of the positive terminal block in the engine bay at the bulk head that would be great!!

I think you may have connected a positive lead to an earth

The small wire that runs across the bulkhead is the feed to the fusebox

Heres a pic of my 318i just as I was converting it to battery in boot

liam012 wrote:am guessing it is to do with the small wire blsck wire that comes with the fat positive wire from the boot to the bulk head positive block. where does the small black wire go? i had it wired to the the group of red wires from the turret.

Red wires from the turret

You shouldn't have ANY red wires connected to the turret (assuming you mean the earth point on the drivers side suspension turret). This is an issue in itself, but also connecting the smaller wire that runs from the battery to the same point (same assumption as above), then you're lucky not to have torched the whole car.

Ian.

lol!! no i completely got that wrong in my effort to explain clearly !!
i knew enough not to join the group of red wires tothe turret!!

here goes:

i hooked all red wires to the positive terminal, no bother.

but i hooked one of the red wires (which is actually a group of red wires ) to the black wire which actually comes from the positive of the battery -

ithought because it goes back to the positive of the battery it wouldnt matter

its hard to explain clealrly

lots of reds joining to a little wire will overload it and melt

You would think the black wire going back to the battery would have overloaded/melted

funny thing is i see that small black wire along side the thick battery wire on a few cars now attached to the top bolt of the three bolts next to the positive terminal.

there is no continuity between that top bolt and positive, the wire just seems to sit there.

i wish i had the nads to plug the battery back in i have the loom replaced but am stull worried i havent sourced the problem.

here's my motor:



v = earth turrets (earths only!)
iv = fuse box feed
iii = group of red wires (engine loom feeds - dme relay etc)
ii = starter feed
i= the black wire coming through with the fat wire - as of yet attached to nothing (i did have iii atached to this earlier when they melted)
its on the top bolt which has no continuity/connection with poistive \9but the wire itself i beleive is a positive oming from the battery)

Your last picture is same as how mine is wired, with the little wire all on its own doing nothing, i thought about it but never changed it and its been like that for 12 months with no problem, somebody must know what the wire is for

Red is 12 volts permanent live on BMW's - usually unfused.
Black is also a colour used for live wires.
Earth wires are brown, and occasionally brown/orange.
These are the colours of the sheath over the copper, not an outer sheath which can be black on any wire!
The large wire from the battery + terminal goes to the large stud on the 'phantom' battery terminal, and wires from here feed the starter motor (and on to the alternator), and the fusebox.
The smaller wire from the battery + terminal goes immediately through a fusible link, then through the car to the smaller terminal of the phantom terminal. The power feed to the engine loom connects to this terminal.
What exactly have you been doing to the car that required all the wiring to be disconnected? Any wiring changed?

well i replaced the loom
this time i have the small blackwire unconnected like it is on my friends card and everything seems to be fine,
apart from missing on a few cyindrs...

i am afraid to attach that small wire to the terminal, is there any test i can do o see if its safe?

You replaced what loom with what loom? Exact details required!

ok
i would like to know what to do with this one black wire so i'l try and explain the loom!

the car is a 320i 1988
it has the original fusebox and fusebox loom ie lights/cabin wire.
I presume originally it was front battery.
the engine loom i am using is from a 325 sport.
rear batery conversion too so i have the phantom terminal pictured as is above with the unconnected black sister wire coming through with it.

i would love to know what to do with this wire!

as you said brian this black wire should be connected to the smaler part of the phantom terminal but the only difference between now and when the last loom melted is the replaced engine loom and not connecting up this wire.
the car starts and runs, the engine loom is connected to the large phantom terminal instead of just this small blak wire so thats giving it power.

maybe the problem was with the old loom that melted - maybe i did wire it fine but it was buggereed before i fit it - upon coser inspecion the melt happend from the three turret relays where it is completely melted down along the loom to the rear of the block where it is only partialy melted. It also seems the relays are quire old and i am guessing even corroded, they are quite rough looking.


what i would like to do is take the power feed from the engine lom and connect it to my currently nconnected black wire as thats the way it should be. however i am afraid of the melting again and wondering can the multimeter be of use to test before i hook them up.

thanks

also whats the point of having the fused smaller black wire from the + of the battery if it just ends up on the phantom terminal anyway whichis fed by the main unfuesd + from the battery.
unless that small wre feeds power intothe car/cabin area before it comes out in the engine bay front battery tray area?

if that is the case could this unconnected wire explain my wipers that start and dont stop and my windows that dont goup and down ( though the lights on the switches come on and i am sure i can hear the windows try when i press the switch - not opened for a year though...) dont really want to troubleshoot those problems in this thread - only curious if they have anything to do with my currently unconnected black wire,

Isn't that terminal/bolt you have/had the small wire from the battery going to Earthed?
I don't have a car here with a rear battery and so can't check this end.

no its actually just a bolt passed though plastic so is neither + or -.

liam012 wrote:no its actually just a bolt passed though plastic so is neither + or -.

If thats the case and the back of it isn't earthing on the body then obviously it makes no difference if its attached or not so thats not your problem.

btw the wipers and windows will get their live feed from the fuse box wiring that you have connected to the live.
The windows are probably just stuck and the wiper problem is more than likely the motor as per usual.

The reason for the second battery cable and the two phantom + terminals is all to do with voltage drop, voltage spikes and starter currents. BMW knew what they were doing when they designed it, trust me.
Now that I know its a 88' car fitted with a Sport loom (you still didn't say what year!), I think I may know what the problem is!
Go to the 'engine swaps forum' and read a sticky I put there, warning about engine swaps.
I think you may find it relevant!!

Brianmoooore wrote:The reason for the second battery cable and the two phantom + terminals is all to do with voltage drop, voltage spikes and starter currents. BMW knew what they were doing when they designed it, trust me.
Now that I know its a 88' car fitted with a Sport loom (you still didn't say what year!), I think I may know what the problem is!
Go to the 'engine swaps forum' and read a sticky I put there, warning about engine swaps.
I think you may find it relevant!!

I'm glad you mentioned that sticky on here Brian as i hadn't noticed it before!
That'll be the reason for the re-wire i had to do on that 318i to M30 conversion not long ago then.

ok!
so theengine loom that melted up had red yellow on pin 20 and that is now all melted.

luckily the replacement engine loom has pin 20 brown same as on the car plug so they are both earths?

now, i checked the condition of the brown wire on the fusebox side and it is bubbled plastic but not melted -

checked under the glovebox and there appears to be no damage - do you think thats the extent of the engine on the fusbox side?



so now that pin20s match up as brown i can safely attach the black little wire to the + block.

i have noticed though that a few of the pins aren't matching up though so will report back!

c101
fusebox side engine side
1. blue blue
2. blu/blk grn/ylw
3. xxx xxx
4. brn/prpl brn/prpl
5. brwn/black brown/green
6. grn/yelw grn/white
7. grn grn and extra lime green wire
8. ylw/whit blck/white
9. blk blk
10. grn/prpl blue
11. blu/whit grn/white
12. xxx grey
13. red/prpl grn/prpl
14. ylw/blu black/white
15. blk/grn blk/grn
16. xxx blk/white
17. xxx xxx
18. blck/ylw blk/ylw
19. xxx xxx
20. brown brown

of particular concern are: 2-5-6-8-10-11-12-13-14-16

i amtotaly lost here - if anyone has the time to look at those colors and help i would really appreciate it.
thanks

liam012 wrote:c101
fusebox side engine side
1. blue blue
2. blu/blk grn/ylw
3. xxx xxx
4. brn/prpl brn/prpl
5. brwn/black brown/green
6. grn/yelw grn/white
7. grn grn and extra lime green wire
8. ylw/whit blck/white
9. blk blk
10. grn/prpl blue
11. blu/whit grn/white
12. xxx grey
13. red/prpl grn/prpl
14. ylw/blu black/white
15. blk/grn blk/grn
16. xxx blk/white
17. xxx xxx
18. blck/ylw blk/ylw
19. xxx xxx
20. brown brown

of particular concern are: 2-5-6-8-10-11-12-13-14-16

i amtotaly lost here - if anyone has the time to look at those colors and help i would really appreciate it.
thanks

All this is as it should be. Many of the colours on the engine side of the C101 are different to those on the car side.
One thing you should do is cut away the brown wire connected to pin 20 on the car body side. Open up the fusebox and cut it there as well, to isolate as much of it as possible, as it may have melted into other wires
It isn't required on your car and wasn't required with the original engine. It's apparently a 'left over' from when E30's had two pin brown
temperature sensors.
The same wire also causes problems when people rewire the injector loom plug and socket on M20 engines, as they find an extra wire on one side of the connector with no matching wire on the other.

thanks brian thats super news all together.

i was worried the grey wire on the engine loom 12 was something important and not being picked up on the car side of the c101.

thanks again.

a lucky escape in the end when all said and done..

one last question!

do you know that pin in the door shut thats basicly a switch to tell the car the door is open? well when i press and release that with my finger i can hear a good solid click from the single purple unloader relay by the passenger door - however when i press the drivers side pin i hear no click from the relay - interestingly though the opening of the door on the drivers side activates the ceiling light when on the right setting but the passenger door does not activate the light.... the window is not working on that side either -
any ideas?

i almost feel cheeky asking after getting such good help already!!!

thanks

Grey wire on 12 is for the engine management warning light fitted on US models. (Connect a small 12 volt bulb between this wire and switched ignition live, if you want to connect it up.)
The purple relay you can hear is not an unloader relay - it's the relay fitted to UK (only?) models, that switches the power feed from ignition live to permanent live when the front doors are open.
Each door pin switch consists of two switches in one. One section works the interior lights, and the other section works the relay. It sounds like you have a problem with the different halves of the switch on each side.
Unscrew the single cross head screw that holds a switch in, pull it out and pull off the two spade terminals. Don't let one spring back through the hole, or you'll have to do some dismantling to retrieve it!
Clean up the switches and check for a thin sliver of black plastic that forms at the contact point. Cut this sliver off carefully with a craft knife, if it's there. Apply a film of silicon grease, push the connectors back on (doesn't matter which way around), and refit.

very much appreciated brian, will do that at first light!!

blast

i have no electics on left side of car???

no window - rear lights or front lights?

anyone know whats going on?

Window, if the driver's side works, is probably a result of disturbing the passenger door loom plug in the door pillar, while working on the pin switch.
If the LH tail light and sidelight don't work, you have probably popped fuse 22 somehow.

ok -
after thorough investigation and changing of bulbs i have narrowed down to no left indicators front or rear and no left window.

Is it still coming to the meet though, lol

Do the indicators work with the hazard switch?

no

funny something like this happened to me yesterday was putting a few things back together a mate hooked up the battery then we tried to start her and she would not dash lights were dimming and there was smoke coming out from the steering colum battery was taken off right away so i started stripping round the steering wheel area and found nothing no melted wires so i hooked the battery back up again and she started no bother what till hell could this be dont want her burnt out