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   Speedo sensor (yes another one) Empty Speedo sensor (yes another one) on Sun Jan 12, 2020 8:59 am

tinyspuds

tinyspuds
Platinum member
Platinum member
Morning all,
While I fitted my new clutch the FD was sitting around the shop with the speedo sensor still fitted. It has previously worked fine and wasn’t abused while it sat on my bench.

After refit, no work.

The rest of the cluster still works fine so probably not an earth problem at that end.

The self cancel indicators don’t work, another indication that the sensor signal isn’t getting through.

I’ve deoxed the connector behind the side panel.

I’ve tried the soldering iron trick, not a flicker.

I’ve multi metered the connector behind the side panel and get a reading of around .3 V AC at tickover in first and this value seems to increase with engine speed.

The last post I’ve read on this says to expect a reading of around .1 V AC. It seems like if I’m getting a reading at all, then the sensor is probably working, regardless that it doesn’t produce any of the meter readings I’ve seen referenced here.

My questions are:

if I’m getting any reading of any value at the connector that increases with engine speed should I be looking further upline for a (probably connector) problem or could the wrong numbers still indicate a faulty sensor?

I know that there is a gap tolerance dimension between the sensor tip and the FD pickup, my sensor tip is almost flush with the sensor case, issue?

Is there a resistance (or other) test that I can do with just the sensor through to the first connector or would that only indicate connectivity rather than proper functionality?

Not stressing on this one as my gps shows speed, but I would like to get the odo and self cancel back on line.

Cheers, Stu



Last edited by tinyspuds on Sun Jan 12, 2020 10:18 am; edited 1 time in total


__________________________________________________
1985 BMW K100RT + Hedingham HUB and LL’s. VIN 0028106. (Not blind to the irony of an April 1 production date).
2007 HD883 Sportster. Bobbed and bettered.
1954 Royal Enfield 350 Bullet. Original.
    

2Back to top Go down   Speedo sensor (yes another one) Empty Re: Speedo sensor (yes another one) on Sun Jan 12, 2020 9:49 am

Dai

Dai
Life time member
Life time member
There's two variants of the sensor; one's easy to break and the other isn't. Piccy please?


__________________________________________________
'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)
    

3Back to top Go down   Speedo sensor (yes another one) Empty Re: Speedo sensor (yes another one) on Sun Jan 12, 2020 10:23 am

tinyspuds

tinyspuds
Platinum member
Platinum member
Can't do piccy atm, on way to panto (oh yes I am) but it's the one that fixes with a single Allen bolt at the rear of sensor and a T connector behind the side panel.


__________________________________________________
1985 BMW K100RT + Hedingham HUB and LL’s. VIN 0028106. (Not blind to the irony of an April 1 production date).
2007 HD883 Sportster. Bobbed and bettered.
1954 Royal Enfield 350 Bullet. Original.
    

4Back to top Go down   Speedo sensor (yes another one) Empty Re: Speedo sensor (yes another one) on Sun Jan 12, 2020 3:06 pm

Dai

Dai
Life time member
Life time member
They're all like that {sigh}. Are you sure you can navigate to North Wales?

Seriously though, most are a sealed unit with a single screw to hold it to the FD. There's one type which has two screws in it - this type can be taken apart. It's not sealed very well, so water can get in and corrode the terminals. I had one like this, fixed it by soldering in new wires, sealed it with epoxy, ran it for a few days and then introduced it to the bin. I just didn't trust it not to fail again.


__________________________________________________
'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)
    

5Back to top Go down   Speedo sensor (yes another one) Empty Re: Speedo sensor (yes another one) on Sun Jan 12, 2020 5:00 pm

tinyspuds

tinyspuds
Platinum member
Platinum member
Piccy tomoz. I'll also put a jumper across that first connector because that's really the only component I've touched. 
And it's unfair to ask about Wales, I won't know the answer til I get there.  Very Happy


__________________________________________________
1985 BMW K100RT + Hedingham HUB and LL’s. VIN 0028106. (Not blind to the irony of an April 1 production date).
2007 HD883 Sportster. Bobbed and bettered.
1954 Royal Enfield 350 Bullet. Original.
    

6Back to top Go down   Speedo sensor (yes another one) Empty Re: Speedo sensor (yes another one) on Sun Jan 12, 2020 5:21 pm

charlie99

charlie99
VIP
VIP
you can measure the sensor at the connector \
if some low resistance , could be ok ... if none ...its toast , not to discount that the connector itself may be faulty

do any measuring without any electrics turned on

there is usually some small voltage going to the sensor from the speedo (dc offset from the amplifier input )

hope that helps


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OSpeedo sensor (yes another one) 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 ..
    

7Back to top Go down   Speedo sensor (yes another one) Empty Re: Speedo sensor (yes another one) on Mon Jan 13, 2020 10:32 am

tinyspuds

tinyspuds
Platinum member
Platinum member
Speedo sensor (yes another one) Img_2016
Jumped connector, still no response. Re-tested for continuity off the bike, no show.
Removed sensor from body, the push fit wires were a bit cruddy and felt loose in the housings.
Ordered a one used from Motorworks. Thanks for the input.


__________________________________________________
1985 BMW K100RT + Hedingham HUB and LL’s. VIN 0028106. (Not blind to the irony of an April 1 production date).
2007 HD883 Sportster. Bobbed and bettered.
1954 Royal Enfield 350 Bullet. Original.
    

8Back to top Go down   Speedo sensor (yes another one) Empty Re: Speedo sensor (yes another one) on Mon Jan 13, 2020 11:57 am

Dai

Dai
Life time member
Life time member
Yup, that's the easy-break version. Take the small screw out, push the cable through the hole (don't try and pull the housing cover) and if you're lucky, you'll expose the two terminals. What I did was get a look at the terminals and found one was a broken green mess, so I cut the wires and pulled the cover off. There was just about enough brass left after cleaning to solder two new wires on.


__________________________________________________
'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)
    

9Back to top Go down   Speedo sensor (yes another one) Empty Re: Speedo sensor (yes another one) on Thu Jan 16, 2020 11:07 am

tinyspuds

tinyspuds
Platinum member
Platinum member
@Dai wrote:Yup, that's the easy-break version.

Spot on Dai. My used replacement arrived and it is the sealed unit variety. Obvious straightaway that its a more robust bit of kit, and it works.
Glad I didn’t waste my money on that Ordnance Survey map of Wales, which also arrived today.Speedo sensor (yes another one) 44271


__________________________________________________
1985 BMW K100RT + Hedingham HUB and LL’s. VIN 0028106. (Not blind to the irony of an April 1 production date).
2007 HD883 Sportster. Bobbed and bettered.
1954 Royal Enfield 350 Bullet. Original.
    

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