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]


1Back to top Go down   Flashing bulb monitor dash light. 91 K75s Empty Flashing bulb monitor dash light. 91 K75s on Sun Nov 22, 2020 8:45 pm

MartinW

MartinW
Life time member
Life time member
A new to OZ Kiwi brick and owner has been trying to get his bike registered. The bike has obtained a mod sticker but now needs a roadworthy. I've talked the owner through most of the problems except for one. I have yet to see the bike but a few of us will be descending on him on Wednesday. The bike had two problems one was the ABS light on permanently, this was temporally fixed by removing the ABS relay. When time permits we'll look further into either fixing it or removing the ABS, owners choice. The next problem is puzzling, the bulb monitor light is flashing when the ignition turned on and continues to flash when started. He has checked that  all the  globes are functioning and applying the brakes does not stop the flashing. I have never seen a brick with a flashing bulb monitor light. I've traced the wiring diagram and I can't see a reason for it to flash. We will be taking a full set of relays and test lights multimeters and jumper wires to hopefully sort out the problem. The problem has only occurred since the bike landed in OZ. Any ideas appreciated. In the mean time I'll puzzle over the diagram.
Regards Martin.



Last edited by MartinW on Tue Nov 24, 2020 9:39 pm; edited 1 time in total


__________________________________________________
K75s Hybrid
    

2Back to top Go down   Flashing bulb monitor dash light. 91 K75s Empty Bulb monitor on Mon Nov 23, 2020 12:01 am

daveyson

daveyson
Life time member
Life time member
You can remove the bulb monitor unit as well, and fix it after the roadworthy. I think at motobrick there is a thread "bulb monitoring unit pinout" that shows how to bridge the pins with a photo, as a substitute, while the monitor is removed.

Maybe unplugging or masking the K pin from the monitor might do the job.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
 ~120,000 km
    

Laitch

Laitch
Life time member
Life time member
The bulb monitor light is part of the ABS warning scheme. There are two relays involved with the early ABS scheme—the ABS relay and the ABS warning relay. You've got one of them and need to remove the other, not the bulb monitor itself.

Flashing bulb monitor dash light. 91 K75s Scree114


__________________________________________________
1995 K75 81,000 miles
Flashing bulb monitor dash light. 91 K75s Usa-lo10
    

robmack

robmack
Life time member
Life time member
The BMU indicator is dual-purpose on an ABS-equipped K75.  If an ABS fault is detected, both the ABS indicator and the BMU indicator will flash in unison.  Since your buddy removed the ABS relay, the ABS indicator is not flashing.  I guess your query is how to stop the flashing.

See this page to understand the ABS faults:  https://ibmwr.org/index.php/1998/09/01/abs-diagnostics/.  

See this page to understand how to reset the ABS: https://ibmwr.org/index.php/1998/04/01/abs-fault-clearing/


__________________________________________________
Robert
1987 K75 @k75retro.blogspot.ca
http://k75retro.blogspot.ca/
    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
Has the owner cleaned all the connections in the brake light circuit including the bulb monitor pins as well as the bulbs and sockets? Wouldn't hurt to clean the grounds as well.

I recently had a problem with an intermittent front brake switch that the bulb monitor didn't like. It might help the troubleshooting to bypass each switch individually to see if it is the problem. Jumper the switch in question, turn on the ignition, activate the other brake and see if the flashing stops.

As I seem to recall, the monitor works by checking the current flow to the brake light filament when the front and rear brake switches are closed. A dirty switch contact or a bad electrical connection can reduce the current flow to the bulb enough to trigger the monitor. It's another reason why LED bulbs require shunt resistors.


__________________________________________________
Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

MartinW

MartinW
Life time member
Life time member
I can understand the warning light being on solid. But it's apparently flashing and that doesn't make a lot of sense. Hopefully it will all fall into place or not on Wednesday it's hopefully something simply stupid. 🇧🇭He is in the process of cleaning connections but has not reported success as yet. I might take my wiring diagram for old people along, courtesy of a friend. Small for young eyes, medium for middle aged eyes, large for nearly blind as bat fossils.Flashing bulb monitor dash light. 91 K75s Pb230210
Regards Martin.


__________________________________________________
K75s Hybrid
    

7Back to top Go down   Flashing bulb monitor dash light. 91 K75s Empty Bulb monitor on Mon Nov 23, 2020 1:09 am

daveyson

daveyson
Life time member
Life time member
I'll spose if the light is on solid, that warns of a normal fail, if flashing warns of an ABS fail, so not as serious.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
 ~120,000 km
    

TacKler

TacKler
Life time member
Life time member
It means the ABS electronics are not working.  Up to you if you wish to fault find it.  What I have done is cover up the offending flashing lights.  

The choices are live with it, cover up the flashing lights or remove the ABS modules.  I say this because even though there is a basic fault finding method involving the number of flashes on a LED, it can take a while  Sleep  Just ask Duck.  

Motorworks used to sell a home made kit and I will probably get around to sorting mine out one day when I have the patience and a whole day to put aside  Flashing bulb monitor dash light. 91 K75s 61740  I believe one of the main culprits was not flushing the ABS brake fluid regularly and the modulators become gummed up.  Meanwhile the brakes will work just fine.  

As ABS was not introduced on K75s till 1990, I am guessing the '89 (Kiwi) model has a VIN date of late '89?  Not sure if ABS was ever an option for 75S models in Oz, because mine was a factory ordered model and ever so slightly different to regular models here.  Although my '94 75RT was originally fitted with ABS.  

If you wish to know more then Toshi's website in Japan is the place to visit.  

I'm not sure whether ABS would require mandatory compliance for a roadworthy inspection if the brakes work.  I do hope this helps and allows you to make an informed decision.


__________________________________________________
Red 1991 K75S
    

MartinW

MartinW
Life time member
Life time member
We might be on the track for a solution. Dan found some more information which led me to an ABS wiring diagram. Apparently there are two relays for the ABS one is the ABS relay the other is the ABS warning light relay. We might have to do a bit of relay juggling. I'm trying to find out the pin configuration to see if we can get them from an automotive supply shop.
Regards Martin.


__________________________________________________
K75s Hybrid
    

Dai

Dai
Life time member
Life time member
Martin: I'm probably teaching my granny to suck eggs, but please be aware that the four-pin and five-pin micro-relays have different DIN-standard pinouts. Unlike the 'normal' size relays, you can't replace a four-pin micro-relay with a five-pin micro-relay and expect it to do the same job. You'll get a permanently-on circuit.


__________________________________________________
1983 K100 upgraded to K100RS spec, 1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

MartinW

MartinW
Life time member
Life time member
Thanks Dai, at the moment I'm trying to borrow a couple of relays off a mate who has a parts bike with ABS. I've been down the BMW's relay pin configuration before. I was told Holden Commodores used the same configuration, but I was never given the year or model.
Regards Martin.


__________________________________________________
K75s Hybrid
    

MartinW

MartinW
Life time member
Life time member
We had our workshop day at Bruce's to try and rectify his ABS problem.  The event was well catered for by Bruce and his lovely wife Annie who are now spoiled the crew. We had a pretty full attendance Mick, Paul, Dan and Gary. After a couple of relay replacements the battery went dead. Dan then volunteered up his battery. Even with both relays removed the light was still flashing. After reading the fault codes it came up with a relay fault and a brain fault. Replaced the relays and the brain with a spare set. Did a few resets and short rides still the same fault codes. Did a few swapping back and forth with no results. So in order to get it registered both the relays and the brain were removed. Once he gets it registered we might have another go at solving it.
Regards Martin.


__________________________________________________
K75s Hybrid
    

MartinW

MartinW
Life time member
Life time member
Pictures and catering courtesy of Bruce's wife Annie.Flashing bulb monitor dash light. 91 K75s Abs_da10
Flashing bulb monitor dash light. 91 K75s Abs_da11
Flashing bulb monitor dash light. 91 K75s Abs_da12
Flashing bulb monitor dash light. 91 K75s Abs_da13
Flashing bulb monitor dash light. 91 K75s Abs_da14
Flashing bulb monitor dash light. 91 K75s Abs_da15


__________________________________________________
K75s Hybrid
    

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