[peterux]

Originally Posted by mcramsay

So I tried with the capacitors and no luck, when connected across the signal and ground they temporarily stopped the interference and then it all started again.

I then looked at running a new cable in the transmission tunnel, extremely difficult with the car on the floor and floors bolted in. Very frustrated at this point... Iva is only 3 weeks away.

And then I remembered I had an old acewell reed switch sender and Magnet left over from a previous project, this is a non powered sender only switching to ground. Took a punt and dug it out and it fitted in the same sender hole as the previous sender, stuck the magnet on and wired it up with the original troublesome wiring And hey presto it seems to work, sat with the electrics on for over and hour with the speedo in calibration mode, it counted pulses and it should and when in running mode the speedo sat at zero the whole time, previously with the Hall effect it would count around 50 pulses per second in calibration mode and when in running the needle was full scale. I need to do a full test but I think I have cured it. Car Is all back together and should be fully 100% finished for iva by Friday, then I can have two weeks off before it heads back to marlin it's test.

Shame the capacitors didn't work but glad you got it fixed. Good luck with your IVA!!