BMW K bikes (Bricks)

You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]


Mike101

Mike101
Silver member
Silver member
Some of you may remember that i had a small fire on my k100LT a few weeks ago.  I was hoping that is was just the wires from the ignition barrel to the loom connector that had gone but alas not.

I finally got around to stripping it down last saturday and found that the damge is from the ignition barrel right through the main loom and almost up to the fuse box.

So i need to replace the main loom.

I need help on the following points please.

1.  Is the 4v loom the same as the 2v loom..mine is an 87 2v.

2.  All advice and help welcome on home to do this.  It seems like its just a unplug, replace and plug job but and i missing something?

3.  What else might have been damaged?

4.  Why didn't the fuse blow shutting off power from the battery?

Help please.

Mike


__________________________________________________
K100LT 1987 Gold and not Beige
XT660Z Tenere
    

RicK G

RicK G
admin
admin
The 4v loom isnt the same, it could be modified to do the job but if at all possible get a 2v loom.
There are many wires in the main loom that arent fused because they feed to distribution points that are then fused as seperate items and if one of those live wires was burned through then where there aint no fuse it cant blow.
When I built my yacht every wire that left the control panel was fused and the only feed that was not fused was the main cable from battery to the starter via the solenoid.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki
    

Mike101

Mike101
Silver member
Silver member
@RicK G wrote:The 4v loom isnt the same, it could be modified to do the job but if at all possible get a 2v loom.
There are many wires in the main loom that arent fused because they feed to distribution points that are then fused as seperate items and if one of those live wires was burned through then where there aint no fuse it cant blow.
When I built my yacht every wire that left the control panel was fused and the only feed that was not fused was the main cable from battery to the starter via the solenoid.

Thanks for the reply.

Guess i'll have to wait for a loom to appear for sale as there aren't any about at the moment.  I bought this bike to use as a winter hack and so far it's not seen any winter.

Mike


__________________________________________________
K100LT 1987 Gold and not Beige
XT660Z Tenere
    

duck

duck
Life time member
Life time member
Use a 2V wiring harness.  The 4V harness is different enough that it wouldn't make sense to try to kludge one in. 

The power to/from the ignition switched is wired directly to the battery/alternator wiring and is what sends power to the switched items of the fuse block. My term for it would be "pre-fused wiring."

From the couple of burned up harnesses I've seen, when one or more circuits short they heat up the bundled wires enough that they'll burn/melt not only their own insulation but that of surrounding wires they're bundled with as well.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
98 Taxi Cab K1200RS
14 K1600GT
http://www.ClassicKBikes.com
    

walfish

walfish
Life time member
Life time member
@Mike101 wrote:
@RicK G wrote:The 4v loom isnt the same, it could be modified to do the job but if at all possible get a 2v loom.
There are many wires in the main loom that arent fused because they feed to distribution points that are then fused as seperate items and if one of those live wires was burned through then where there aint no fuse it cant blow.
When I built my yacht every wire that left the control panel was fused and the only feed that was not fused was the main cable from battery to the starter via the solenoid.

Thanks for the reply.



Guess i'll have to wait for a loom to appear for sale as there aren't any about at the moment.  I bought this bike to use as a winter hack and so far it's not seen any winter.

Mike
Mike - look on the Motor Works site they seem to have stock

 Advice please - main loom replacement 22936


__________________________________________________
Advice please - main loom replacement Uk-log10 88 K 100  0033026 
   
                            92 K 1100 LT  6455097
    

Mike101

Mike101
Silver member
Silver member
ungaas wrote:
@Mike101 wrote:
@RicK G wrote:The 4v loom isnt the same, it could be modified to do the job but if at all possible get a 2v loom.
There are many wires in the main loom that arent fused because they feed to distribution points that are then fused as seperate items and if one of those live wires was burned through then where there aint no fuse it cant blow.
When I built my yacht every wire that left the control panel was fused and the only feed that was not fused was the main cable from battery to the starter via the solenoid.

Thanks for the reply.



Guess i'll have to wait for a loom to appear for sale as there aren't any about at the moment.  I bought this bike to use as a winter hack and so far it's not seen any winter.

Mike
Mike - look on the Motor Works site they seem to have stock

 Advice please - main loom replacement 22936

I've given MW a call and they are looking for me...they don;t have many staff in at the moment so i'll have to wait until next week to get one.

Is it a mare to change...i'm not looking forward to it at all.


__________________________________________________
K100LT 1987 Gold and not Beige
XT660Z Tenere
    

walfish

walfish
Life time member
Life time member
Iv'e not done one yet, so cannot comment,but, would think using a camera and a labelling system you'd be fine.
This site is always very helpful if you are stuck.

 Advice please - main loom replacement 22936


__________________________________________________
Advice please - main loom replacement Uk-log10 88 K 100  0033026 
   
                            92 K 1100 LT  6455097
    

Inge K.

Inge K.
VIP
VIP
If Motorworks ain't got any in stock....it is a few on German Ebay...both with and w/o ABS.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

RicK G

RicK G
admin
admin
You need to be careful with letting that albino arctic gerbil play with sparklers it may set fire to itself and I dont need to read the headlines here saying NORWEGIAN MAN FOUND EATING ROAST GERBIL.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki
    

Inge K.

Inge K.
VIP
VIP
No problem, Rick...it's burning rather slowly, and he's trained to spit.....
and light the next one......but this time of the year often is a bit hard on the whiskers.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

twincarb

twincarb
Life time member
Life time member
I may well have a spare loom in the basement, not sure if I took one of the connectors off of it but can have a look and see what state it's in. 
It's from a 2v 88 K100


__________________________________________________
BMW K100LT 1988 Matt Black Peugeot Electra Blue (ELX) Colour is now confirmed...
Yamaha Thundercat
Triumph Spitfire (not a bike but hell it's British chaps)
Advice please - main loom replacement 169042 Advice please - main loom replacement 169034
    

Mike101

Mike101
Silver member
Silver member
@twincarb wrote:I may well have a spare loom in the basement, not sure if I took one of the connectors off of it but can have a look and see what state it's in. 
It's from a 2v 88 K100

Cheers...mine is a 2V 1987 K100LT non ABS.

Mike


__________________________________________________
K100LT 1987 Gold and not Beige
XT660Z Tenere
    

George R

avatar
active member
active member
Hi Mike - like you I found out the hard way that BMW have the best system of all to protect the fuses in the fuse box by not fusing any of the main cables. Doh!  I would accept the starter /alternator/battery cable not fused but not the rest. Yvonne at M/W came up trumps for me and between the two harnesses made a good unit. Changing the harness is a b_t_ch of a job but I suggest a digital camera, empty card and a full battery! Any wire you are to move, photograph it first, and also label it using masking tape - once over the wire and join the two tails together. Write with a sharpie what it is and where it connects to. If a joint in the wire, label both ends and mark A1 on on each end for headstock area, B1 on for under tank, C1 on for the Relay box and so on. I realise I am probably speaking to the knowledgeable but you must be methodical and careful. Label EVERYTHING before you start to remove the old harness and check each wire to make sure it has the same colours as the replacement. My 2 harnesses were for the same production year but there were six wires that were not the same colours.
One important thing - TAKE YOUR TIME. 
I reckon it took me two weeks to do the change but I had some repairs to do as well.
If I can help with any assistance do not hesitate to get in touch.
Regards

    

Mike101

Mike101
Silver member
Silver member
Am I missing something but it looks very straight forward to me.

Each connector seems to be almost unique with no two matching in the same part of the bike.

I have undone a few connectors under the tank but I will stop now until I get the new loom so I can compare as I go along.

Please correct me if I am wrong.

Mike


__________________________________________________
K100LT 1987 Gold and not Beige
XT660Z Tenere
    

duck

duck
Life time member
Life time member
You are correct that wiring colors and unique connectors make it pretty easy to swap in a 'new' main harness.

The one exception is the common piston switch that is used for:

- clutch switch
- front brake switch
- rear brake switch (on early Ks)
- choke indicator


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
98 Taxi Cab K1200RS
14 K1600GT
http://www.ClassicKBikes.com
    

RicK G

RicK G
admin
admin
The one I have seen mixed up a few times is the Gear position indicator and fuel tank plug which are the same and under the right side cover. Careful checking of the colours will give you the right plugs.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki
    

acftfliehr

acftfliehr
active member
active member
I would do the following if the Main Loom Replacement is from a salvaged one
 
1)    Unwrap all the tightly wound outer anti chaff tape and inspect the wires for overheating..  I have found 2 cases where the yellow/brown wires in the upper backbone area to be melted together with other wires that were in contact damaged..  These are the yellow wires for headlight power..
2)    The stock wire gauge size on a few key high current demand circuits is inadequate, especially with the tightly wrapped  harness, coupled with the heat of the K100 generated.  This causes increased resistance and lower voltages delivered to the components.
3)    For the headlight circuit, I strongly recommend a kit such as this http://www.easternbeaver.com/Main/Wiring_Kits/wiring_kits.html installed, making the stock wiring merely a control circuit..It would also save on headlamp switches etc….
4)    I would do the same for the keyed ignition switch circuit, making the Ignition switch/Kill switch a control circuit for a relay and bringing fused power to the Yellow/Green after the kill switch to all components downstream.   This ignition circuit can cause one to talk to themselves and seeking mental help with intermittent operation troubleshooting..  This has bit me twice over the years.  The ignition switch is inadequate to handle all the loads on the circuit, coupled with its placement in the “dash” where all the weather related water/dirt etc flows downwards into the contact area…
5)    I have seen at the ignition module for instance where pins are pushed out of their block as you install the connector; make sure all pins are secure into their blocks on your inspection.
6)    I would recommend printing out a colored wire print blown up and taped together, and accomplish a “ring” out of the wires pin to pin, then marking it off on the print (using a friend is a good way to do this)….  This accomplishes confidence that the harness is not going to be your issue if when you get it all together and you have problems in addition to not smoking an expensive component when you have your first “Power On’…
7)    Inspect all grounds (to include the ganged glued grounds taped together in the harness, I soldiered mine as I am not convinced this is a good method for the long haul of connecting wires….  Also inspect all crimped ground eyelet connectors closely.  In the neck area, I soldiered the wires to the crimped areas as these are essential grounds for the Ignition and fuel injection module grounds.  Grounds are important on the bike as most of the Jettronic/ignition system is European style “switchable ground system” in that most components are powered and the circuit is made live by enabling (switching on) the ground side of the circuit.     What makes it even crazier, is that outside of this system, the frame items the power side is the switchable side….

I found a charred wire once leading from the Starter relay to the starter, only in the external area after it exited the relay box, you would’ve thought that the wire would be charred the whole length?!?
9)    Finally, after placement of the harness loosely on the bike, I would use commercially available outer anti chap wrap so the wiring will operate in a cooler environment, as well as making it easier for future troubleshooting access..
 
I am also in the process of rebuilding a harness, and am in the process of taking out the load shed circuit by replacing a “lighting/accessory master switch” instead of this auto feature.  Also I will be installing a Ignition master switch replacing the keyed ignition switch, with a push button starter (both weatherproofed switches).
 
I plan on keeping the turn signals the way they are, Love the switches on the same side as the turning, as well as the auto cancel function..  Will also install LED’s now that the Duck has figured away how to disable the monitoring for failed bulb in the flasher unit…. Thanks to the Mallard on that one…
 
Good luck on your project…

    

charlie99

charlie99
VIP
VIP
some great recommendations

cheers


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OAdvice please - main loom replacement Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum