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Hall effect speed pickup help required ?
Jon Ison - 9/4/13 at 08:22 AM

My speedo stopped working on digi dash, my electrical knowledge goes as far as been able to check power to sensor, its reading 4.5V so assume this is as should be and ok ?

Called ETB no one will be around till Monday of next week, looking on eBay there are lots for sale starting at £2.80, got to be worth a try however the ones I look at whilst all range from 3-30v have different ratings for "differential magnetic force" 20G, 75G for example.

Anyone help me choose the right one to try ?


RK - 9/4/13 at 11:43 AM

I don't know, but mine stopped working too, following a small altercation between my oil pan and the ground. Since I have changed the engine and repositioned the sensor. No avail.


Jon Ison - 9/4/13 at 06:02 PM

100+ views and no answer, this is not gonna beat the locostbuilders collective is it ?


theprisioner - 9/4/13 at 06:02 PM

Is this thread relevant?

http://www.locostbuilders.co.uk/viewthread.php?tid=179239


britishtrident - 9/4/13 at 06:59 PM

Best way to test a Hall Effect is to tap into the output wire and with everything powered look at the change in voltage when the rotating disc is rotated.
If you unbolt the sensor provided it has a power and earth connection you should swipe a small magnetic past it you also get a pulse on the output.
I use hand held oscilloscope for testing Hall Effect sensors on ABS systems but a Digital Multi Meter on the 20 V dc scale should also be OK .
It is best not to test the resistance of the sensor as if you get the polarity wrong you will burn it out.


Most likely cause of problem is (1) air gap too wide. (2) broken internal connection (3) external wire or connector fault.


Jon Ison - 19/4/13 at 07:26 AM

quote:
Originally posted by RK
I don't know, but mine stopped working too, following a small altercation between my oil pan and the ground. Since I have changed the engine and repositioned the sensor. No avail.


Now fixed for 99p, took a chance and purchased 5 sensors off ebay for 99p, fitted one speedo now fine, been a none electronics buff I'm well chuffed, ETB wanted £32 for a complete sensor.

If anyone needs one get in touch can also tell you which wire is which.