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]


jjefferies

jjefferies
Platinum member
Platinum member
Anyway, I'm heading down that bad road 880 to Greg's airhead Emporium on my Silver K75 when I noticed an electrical anomaly. When I hit my turn signals (either one) the turn signals don't work and the clock display fades away to nothing. As soon as I hit the turn signal cancel button the clock display  comes back on. So I'm debugging this at 80mph (indicated) as there were some horn honks before I noticed the lack of turn signal indicators.

Symptoms:
1. turn signal switches (left or right) pressed. No signal indicators or signal lights xc.
2. Clock display fades away to nothing.
3. Pressing the turn signal clear button, the clock display returns. 

Anyone seen anything similar? OBTW, I cleaned the grounds on this machine
a couple of months ago.

best regards
P.S. scored a couple of new keys for the Silver bike at Greg's. Took me an hour to
work thru all the keys but did find two that worked and one that almost worked. Five
bucks for a key ain't that bad.

    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
First thing, I would try swapping the flasher module.  There is a lot of stuff going on in there; turn signal flashing, switching, auto turn off, and the hazard flashers.

The hazard flashers are interesting because they get their power from the same source as the clock if I remember correctly.  This is so they keep flashing after you turn off the ignition.  Even if you don't have the switch for the optional hazard flashers, their circuitry and wiring is contained in the flasher module, instrument cluster, and the wiring harness.

I've had experience with goofy flasher module stuff.  One of them gave me fits on my '88 K100RS.  In my case, the right turn signal and the hazard flashers worked perfectly, but the left turn signal switch turned on the hazard flashers which flashed at twice the normal rate.  The turn cancel switch cancelled the flashers.  Turned out the problem was in one of the integrated circuits that is in the module.  It only took me two or three months of brute force part changing to find the bad part.


__________________________________________________
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
    

jjefferies

jjefferies
Platinum member
Platinum member
@Point-Seven-five wrote:First thing, I would try swapping the flasher module. 
I'm game, Where is the flasher module located?
I'm seeing a single unit with multiple relays.

2nd or third edit. I found one in my pile of stuff. But Someone,
not me, had cut it open and then sealed it back up with Duct Tape.
No telling what its status is. Will try it once I know where to
locate the existing one. If the spare I'm seeing is actually
working I can seal it properly. And in the meantime I'll reach
out to see if I can find one on the cheap. EBay prices are
rather high.

    

jjefferies

jjefferies
Platinum member
Platinum member
Ok found the "turn signal and hazard light flasher" in the control box bucket under the fuel tank. Now to get a nice day to try replacing the module.

If anyone else has helpful comments please post them.

best regards
J.

    

5Back to top Go down   K75 Electrical Anomaly: Turn Signals & clock display Empty Electrical problem Sat Jan 08, 2022 11:32 pm

daveyson

daveyson
Life time member
Life time member
Another quick thing to check is the fuses, without looking at the books I think fuse three and seven, so double check that. Fuses are worth a look cause they're like the weakest link. Give fuse three a good look and clean the contacts (Edit: and check for tight contact) and put a new fuse in. Prob good to change all the fuses to new, they're cheap and they're real old now.



Last edited by daveyson on Sat Jan 08, 2022 11:39 pm; edited 1 time in total


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

MartinW

MartinW
Life time member
Life time member
Sometimes the flasher module were opened up so they could be modified to run LED indicators. The modification involved cutting one of the circuit board tracks. If this is the case the track can be reinstated by careful use of a soldering iron.
Regards Martin.


__________________________________________________
K75s Hybrid
    

jjefferies

jjefferies
Platinum member
Platinum member
@MartinW wrote:Sometimes the flasher module were opened up so they could be modified to run LED indicators. The modification involved cutting one of the circuit board tracks. If this is the case the track can be reinstated by careful use of a soldering iron.
Regards Martin.
I'll look. But would it be obvious?
thanks
J.

    

MartinW

MartinW
Life time member
Life time member
Post number 33 should help.https://www.k100-forum.com/t12582-led-indicators
Regards Martin.


__________________________________________________
K75s Hybrid
    

robmack

robmack
Life time member
Life time member
@jjefferies doesn't state whether his bike is equipped with LED indicators or not.  A modified flasher module will work fine with normal incandescent bulbs.

Fuse 3 is suspect.  Demand for current on red/white occurs when the flashers are activated. If the clock extinguishes with that demand, it means resistance in the circuit is causing a phantom voltage drop.  That drop is enough to affect the flasher and clock loads.  When the current demand stops with the cancel button, the  phantom voltage drop disappears.  I'd follow @daveyson's advice and replace fuse 3 and clean contacts in the fuse holder.



Last edited by robmack on Sun Jan 09, 2022 3:56 pm; edited 1 time in total


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

jjefferies

jjefferies
Platinum member
Platinum member
Thanks to all. A thorough cleaning of all the fuses, particularly #3, has restored functionality to my turn signals and stopped the clock issue. But wish to thank all posters as I now know where the flasher unit is and that I have two spares!! Seriously would like to have LEDs in the turnsignals and may yet modify the already modified flasher unit.

best regards
J.Jefferies

    

Woodie

Woodie
Life time member
Life time member
Switching your incandescent turn signal bulbs out for LED's will still work without the modification to the flasher relay.  The LED's just blink at a much faster rate.  Modifying my own flasher relay is on the winter shutdown to do list.


__________________________________________________
K75 Electrical Anomaly: Turn Signals & clock display Logo2111
1985 K100RT  52667
1990 K75RT 6018570 (project)

"Keep your stick on the ice.  We're all in this together."  Red Green
    

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