K1100 Speedos, so now what???

[KCKBMOA]

Okay, so I've seen the the threads here and more at the IMBWR site regarding the recurring issue of K model Insturments, and mostly speedo/odo problems.:bluduh I called Palo Alto speedometer myself last week, and they reaffirmed the post I'd seen that said they don't work on them anymore. Off the record, at my question, he mentioned that it was because of the returns after repairs; lost porfits. Great, so now what is out there as an alternative? :confused: I've even seen people are resorting to bicycle speedos modified to work on our K's.... now that's sad isn't it? :cry I am willing to tackle the thing myself, but the repair threads all seem to be aimed at the earlier units, soldering jumpers across bad contacts, and mine is supposed to be the "better goretex" unit, with the 2 vents on back.....so much for that. I have had mine apart, and don't see any corrosion on contact pins. Does anyone have a good method to figure out where the problem is? I have confirmed 280 ohms thru the sensor up to the back connector, which is supposed to be normal continuity thru the sensor coil on the final drive. Is there a theory of operation posted somewhere? I'd like to develop a method of bench checking these things. I believe it's a square wave signal from the sensor, so maybe a signal generator could supply the test input. Maybe I can convince my buddy at the local avionics shop to look the thing over if I can give him something to refference. :buds Gettin desperate myself!! KC

[roy]

KC,
NOTE: I am not sure if the K1100 is the same as my K100 so this may or may not work.
On my K100 I could use a Volt Meter to see if the sending unit was functional. Removed the connectors from the back of speedo housing. Using the Clymer manual Identified which pins where for the sending unit. Connected the VOM across these pins and spun the rear tire. VOM should read millivolts. Was a technique described by the local BMW Technician.

On my K100 I also had one of the components on the circuit board go bad. I work with a electronics wizard who actually did the diagnostics and the part cost me less than $4.00.

Option may be to see if you locate a good electronics repair house and maybe tey can check the components on the speedo driver board. Again if like my K100 there are not that many components on this board.

Roy

[wmubrown]

When buying real-estate it's all 'location location location'

With K-speedos it's all about 'contacts contacts contacts'

I didn't catch what the actual problem is, but sounds like you've lost speed indication? Common issues have been gear indicator, needles "sticking", but rarely actual loss of a gage. Currently, mine is always displaying the red "!" indicator, my brake lights work fine, so I'm not sure what it's bitching about.

However, my suggestion is this: a common failure is the connector under the tank where the speedo sensor plugs into the bike harness. Get some ATF-4 automatic transmission fluid, the RED stuff. This stuff is INCREDIBLE for removing oxidation on electrical contacts. You don't need much, but apply some to each pin in the connector, then plug/unplug it a few times to work it in. Test it. If there is no change, and your speedo is truly not working as I am assuming, get a tape head demagnetizer (or better yet, a cassette tape bulk eraser) and place it on the speedo sensor (you don't have to remove it from the final drive) and turn it on. It puts out a 60hz magnetic field which is detected by the sensor and will read about 45 MPH on your speedo. If you see no reading, you attention is now on the speedo harness. Use the same trick (ATF-4) on all the contacts to the speedo unit, reconnect and try again. If still no luck, NOW you need to go inside the speedo unit.

**The demagnetizer trick is from Brian Curry, Jerry Skene, et al procedures for adjusting the K-bike speedo accuracy found here: http://www.ibmwr.org/ktech.shtml under the "INSTRUMENT CLUSTER" heading. Check it out, one or a few of these guys may respond to Email queries also - a good resource!

[KCKBMOA]

Roy and John, Thanks for the input. I am fairly handy with the electrical stuff, and have friends that are better. So working on the boards would be a welcome idea, I'm just hoping to get some kind of road map on the thing first. My Clymer doesn't do much for that subject. I will varify a milivolt output at the speedo head as a check in the box of trouble shooting. I guess I'll take it apart again and look closer at contacts, but I'd like to have a better idea of where the driver is on the ribbon connector etc. That connection under the tank is a good thought also.... sometime the easy thing is overlooked! KC

[wmubrown]

Roy and John, Thanks for the input. I am fairly handy with the electrical stuff, and have friends that are better. So working on the boards would be a welcome idea, I'm just hoping to get some kind of road map on the thing first. My Clymer doesn't do much for that subject. I will varify a milivolt output at the speedo head as a check in the box of trouble shooting. I guess I'll take it apart again and look closer at contacts, but I'd like to have a better idea of where the driver is on the ribbon connector etc. That connection under the tank is a good thought also.... sometime the easy thing is overlooked! KC

Too easy to overlook the easy things sometimes...

ALWAYS check batteries first in portable devices...
<<quick, nervous look to the left, then right>>