Hello,

My Telemetrix speedo has never really worked right using the magnets, its always been a bit erratic, and its definitly not getting any better. I've removed all but one magnet and i get the same, so i think its time to invest in an alternative.

Has anybody used one of the sensors which attatch to the gearbox? Do they go into the socket where the speedo cable should go?

Smiths want 50quid for theirs which i think is bordering on daylight robbery, are there any cheaper alternatives?

Cheers


David

Hi David. I can't understand your problem with the electronic one. Don't know the telemetrix one personally but I've fitted 2 of this type of speedo now and both worked perfectly.

Do you have a tight air gap? I know mine is miniscule but it works a treat.

Is the magnet showing the right pole outwards? Might make a difference.

Or alternatively is the speedo itself just plain faulty, if that's the case then send it back.

Hi Vince,

Its just irratic, so i'll be driving along, and the speed will drop to zero, or say 50% of actual speed etc.

Its definitely down to the magnets either not being close enough or something like that. I was just wondering if its worth fitting one directly into the mechanical speedo drive and saving me the ball ache

Cheers

David

It still sounds like the gap is too large. I welded a bracket onto the back axle and put the magnet onto the prop shaft fitting flange. Gap is probably about 1mm or so. Can take a picture if you like but both cars I've built have both had "very accurate" speedos and have both gone through SVA.

I am using a telemetrix speedo and have had problems with the magnets coming off. Initially I had a very small gap between the magnets and sensor but since resecuring the magnets I have a gap of about 5mm and it works fine. One thing I read on another forum is to make sure all the magnet poles face the same way. My magnets had a small dimple in one side so I fitted the dimples towards the propshaft NNNN. Dont know if magnets being of different poles facing the sensor eg. NSNN would cause your problem but its worth a try