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]


robmack

avatar
Life time member
Life time member
Hi,

I'm wondering if anyone here has purchased an aftermarket speedometer from Ebay, usually sold through Hong Kong and Chinese dealers. These instruments appear like this:



I need to know whether the signals expected by these devices are active low or active high. For example, many models have gear indicators -- do these gear indicators light up when pulled low to ground or raised high to +12V? Same goes for turn signal indicators and high beam indicators.

Thanks for any info.


__________________________________________________
Robert
1987 K75 @k75retro.blogspot.ca
2011 Moto Guzzi V7 Racer
http://k75retro.blogspot.ca/
    

RicK G

avatar
VIP
VIP
The bottom one is the one that I have for my chookie so after Charlie and me have finished messing about with it and the bits we should be able to tell you.

PM sent Rob with the info that came with the item


__________________________________________________
"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats." from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

robmack

avatar
Life time member
Life time member
Well, well. I just found this connection table on one of the Ebay seller's description page for that particular speedometer, Rick.




This indicates to me that the signals need to go low (grounded) for the majority of the indicators to function. You and Charlie will have to see if your 4028 based circuit will function, since I think that chip pulls its outputs high.


__________________________________________________
Robert
1987 K75 @k75retro.blogspot.ca
2011 Moto Guzzi V7 Racer
http://k75retro.blogspot.ca/
    

RicK G

avatar
VIP
VIP
This indicates to me that the signals need to go low (grounded) for the majority of the indicators to function. You and Charlie (no not me just Charlie I lost connectivity with this stuff years ago) will have to see if your 4028 based circuit will function, since I think that chip pulls its outputs high.


__________________________________________________
"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats." from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

robmack

avatar
Life time member
Life time member
I need an expert interpreter for Chinglish. I found instructions for the first pictured tachometer (in the first post). The bloody meager instructions consist of a badly drawn diagram showing the connector pin mapping. This they call the "wiring diagram".

The pins are labelled in typical Chinglish ... totally indecipherable.



I'm trying to interpret the pins labelled "Negative" "Power" and "Memory". I THINK they mean "Ground" "Switched +12V" and "continuous +12V" respectively. Do others agree with this interpretation?

The reason I ask is that when I apply power to "Power" and "Negative", nothing happens on the meter. I think I also need constant 12V but don't want to blow up the instrument in case I'm making a mistake interpreting the wiring diagram (it's not mine).


__________________________________________________
Robert
1987 K75 @k75retro.blogspot.ca
2011 Moto Guzzi V7 Racer
http://k75retro.blogspot.ca/
    

Dai

avatar
Life time member
Life time member
Rob - if it's any help the wiring colours seem to be following Honda specifications. If so,

green is earth
red is unswitched +12v
black is switched +12v
orange is left indicator
light-blue is right indicator
blue is high beam
brown is pilot light (backlighting?)

The rest of them look reasonably self-explanatory?


__________________________________________________
'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

charlie99

avatar
VIP
VIP
hi rob ...you will probably find the unswitched + runs the instruments electronics ....the switched + turns on the display
hope that helps


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
    

robmack

avatar
Life time member
Life time member
Thanks Dai and Charlie, it works once I hook up both red and black to +12V, green to ground.


__________________________________________________
Robert
1987 K75 @k75retro.blogspot.ca
2011 Moto Guzzi V7 Racer
http://k75retro.blogspot.ca/
    

sj2000

avatar
Silver member
Silver member
Robmack, I am interested to see how you connect all the cables, if you don't mind to show the pictures. Thanks.

    

Motorbike Mike

avatar
Life time member
Life time member
I hate to chuck this spanner in the works but I had a Koso instrument (a word I'd use lightly) identical to the bottom image at the top of the thread and the tacho just wouldn't work properly on my K. I tried every way possible to connect it up as per instructions, fitted various filters and the manufactures own device guaranteed to get the thing working to no avail.
I ended up sending it back for a refund. Buy cheap, buy twice rings in my ears again.

Good luck anyway.

    

robmack

avatar
Life time member
Life time member
@sj2000 wrote:Robmack, I am interested to see how you connect all the cables, if you don't mind to show the pictures. Thanks.
I didn't buy or hookup this speedometer to my motorcycle. I borrowed a gauge similar to the first one pictured at the top if this thread in order to design and test a gear indicator board. Once I finished the board, I returned the speedometer to its owner.

I documented my K75 build on my blog page if you care to read.


__________________________________________________
Robert
1987 K75 @k75retro.blogspot.ca
2011 Moto Guzzi V7 Racer
http://k75retro.blogspot.ca/
    

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