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ETB DigiDash 2 - Speedo Interference from Ignition
Edge - 25/5/17 at 01:24 PM

I have a DigiDash 2 with data logic module and a speed sensor with magnet on one of the front hubs.

If I roll the car without the engine running the speedo seems to work, registering a couple of MPH.

When I start the engine (stationary or rolling) then I get interference and the speedo oscillates 100-130mph and seems to be engine revs sensitive.

Anyone have any wisdom as how to fix this with a basic set of tools and a multi-meter (think I would need some kind of oscilloscope to see the interference on individual wires?)

I'm based in Woking, Surrey if there happened to be anyone local who could help.

Thanks in advance!


gremlin1234 - 25/5/17 at 02:21 PM

well the best thing to do is first get rid of the noise, you may be able to find any particularly noisy components with a cheep 'transistor radio'
secondly, adding capacitors on the power supply, near to the instrument panel
then ether shield, or use twisted pair wiring to the sensors.
and possibly add pull-up or pull-down resistors on the sensors.


loggyboy - 25/5/17 at 02:26 PM

Check all the earths - always first place to start.


bi22le - 25/5/17 at 08:11 PM

quote:
Originally posted by loggyboy
Check all the earths - always first place to start.


Thats my first point of call as well.

The speed sensor is an open closed a fair I thought so I cant imagine interference screwing that up a lot.

Try just unclipping the sensor wire and fly- wire it over to the hub so it is well away from any loom.