Hi all, just getting ready to test my inop K100 speedo with Karamba, and wanted a little clarification...

This thread: https://www.k100-forum.com/t2038-karamba-speedometer-calibration-program-tutorial

Says you should connect power to pin 6, speedo signal to pin 22, and ground to 23.

Now, I'm a little confused here...power is 12v from a benchtop transformer to pin 6. That's easy enough.

Signal to pin 22...is this the tip/ring of the special cable? (yellow wire in image)

Ground to pin 23...surely this goes to the ground of my benchtop transformer, yes? Where should I connect the ground pin of the audio plug? Also to pin 23? (black wire in image)

Got it figured with some help from a Motobricker...

Connect +12v to pin 6 (from power supply)
Connect pin 13 to power supply ground

Connect pin 22 to +sig (tip or ring of 3.5mm audio jack)
Connect pin 23 to sig ground (shield of 3.5mm audio jack)

My speedo head works perfectly...the sensor meters open. My odometer is also inoperable. I'll investigate that shortly.

Your open-circuit speed sender might be due to a broken wire rather than a dead pickup coil. I'd try to isolate the problem and repair it if possible, before declaring the sender dead.

For example, stick a couple of common pins through the wire insulation near the sender and measure the resistance. If you get a solid 280 Ohms, then maybe you can splice in a new wire or locate and repair the break. If it still measures open circuit, then it's time to get a new sender.

robmack wrote:Your open-circuit speed sender might be due to a broken wire rather than a dead pickup coil.  I'd try to isolate the problem and repair it if possible, before declaring the sender dead.

For example, stick a couple of common pins through the wire insulation near the sender and measure the resistance.  If you get a solid 280 Ohms, then maybe you can splice in a new wire or locate and repair the break.  If it still measures open circuit, then it's time to get a new sender.

Just tried that...good idea, but unfortunately, no dice. Skived a bit of insulation off at the soldered joint, and still got a reading in the neighborhood of 200 Megaohms. Damn near open.

This sensor is pretty crusty...it used to work intermittently, but I probably but the nail in it's coffin removing it.

200 meg ohms ...crikey you must live near the north pole or in sudi arabia ..never seen a value that high ....anywhere ...anytime  especially on a standard type meter up to $200 dollars ...perhaps up to 600 dollars if you prefer to throw money at a fluke .


most meters stop at 20 megohm   period

are you sure you have the range setting set right ?

just a question  don't doubt your sincerity

I work in electronics design and manufacturing as a technical writer... We've got some neat toys. That reading was taken with a recently calibrated auto ranging Agilent meter.

The fluke I have at the shop is really old. It's been acting up lately, and you have to set the dial switch juuuuuust right to get it to work. I don't really trust it, but I haven't replaced it yet. Thus my desire to verify the weird behavior I was seeing.

charlie99 wrote:200 meg ohms ...crikey you must live near the north pole or in sudi arabia ..never seen a value that high ....anywhere ...anytime  especially on a standard type meter up to $200 dollars ...perhaps up to 600 dollars if you prefer to throw money at a fluke .


most meters stop at 20 megohm   period

are you sure you have the range setting set right ?

just a question  don't doubt your sincerity

http://uni-trend.com/productsdetail.aspx?ProductsID=617&ProductsCateId=746&CateId=746

I use one of these Charlie, €30 something ( if whats left of my memory serves me correctly ) in Maplin a few years ago. It has a 200 M Ohm range.

Avenger GT wrote:

charlie99 wrote:200 meg ohms ...crikey you must live near the north pole or in sudi arabia ..never seen a value that high ....anywhere ...anytime  especially on a standard type meter up to $200 dollars ...perhaps up to 600 dollars if you prefer to throw money at a fluke .


most meters stop at 20 megohm   period

are you sure you have the range setting set right ?

just a question  don't doubt your sincerity

http://uni-trend.com/productsdetail.aspx?ProductsID=617&ProductsCateId=746&CateId=746

I use one of these Charlie, €30 something ( if whats left of my memory serves me correctly ) in Maplin a few years ago. It has a 200 M Ohm range.

well I stand corrected ...thanks for the link mate ....but honestly never seen a quoted figure of over 10 meg resistance without some high voltage being applied .well more than 9 volts available from the meter anyhow ...unless there is a very tricky inverter circuit involved to generate those voltages required ...

again thanks and still never seen one in real life yet

cheers