Hall Sender Testing

[Slaydog]

Hi, does anyone have a working link to the idiots guide to testing the hall sender? Looking at other posts just return a dead link.

So far I’ve tested that I get 12v at the positive terminal of the ignition coil and also get around 11v when testing the two outer pins of the hall sender connector. Also get a spark from main HT lead when earthing the middle pin.

Just a bit stuck what to do next.

Thanks
Ben


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[AngeloEvs]

There is little you can do to test it other than try a replacement. Is your question due to an ignition fault?

[Slaydog]

Yep, I’m having a weird experience not being able to start after engine has warmed up. Doesn’t seem to be fuel supply, plugs all ok and decent enough voltage to the coil. Just experiencing occasions stalling at low idle and not being able to start again if stopping after a decent run out.

Thx

[ash1293]

Sounds exactly like the problem I had. At first thought a duff coil/amplifier as no spark although would start fine after a while.
New coil & amplifier and thought problem solved but happened again, no spark.

Hall sender changed and all was good.

[bigherb]

Hi, does anyone have a working link to the idiots guide to testing the hall sender? Looking at other posts just return a dead link.

So far I’ve tested that I get 12v at the positive terminal of the ignition coil and also get around 11v when testing the two outer pins of the hall sender connector. Also get a spark from main HT lead when earthing the middle pin.

Just a bit stuck what to do next.

Thanks
Ben


Sent from my iPhone using Tapatalk

That is basically it. You eliminate every thing else by scraping the centre pin of the distributor Hall plug to earth, if you get sparks then every thing else is working. As long as there is more than 5V across the two outer pins of the plug and the distributor is actually rotating, then the Hall sensor is at fault.
Also, check you still have near 12V at the positive terminal of the coil whilst you are cranking the engine as well.
 

[Slaydog]

Thanks both. Tested the voltage on the ignition coil when starting the engine and it dropped to 7.5 before jumping back up to 12+. Think it is supposed to only drop to 9.6 so could it be coil issue maybe? It’s only a year old frustratingly.

Just to add - if I put a booster on the battery terminals it starts again and I’m able to continue without cut out (until the next time). Wondering if the extra boost also helps add a bit of voltage at the coil or this is still potential hall sender issue.. (??)

Just checked the resistance on the coil (green) per this blog and primary is reading 1.2 and secondary just over 4.

Should be 0.5-0.8 primary and 2.4-3.5 secondary.

https://www.brickwerks.co.uk/brickwerks ... ion-coils/


Will get there eventually I’m sure.

[AngeloEvs]

Did you short the meter probes before taking resistance measurements to check that you had 0 ohm reading? Some digital voltmeters will read a low resistance of the meter leads themselves when shorted together and, if there is a reading, it needs to be subtracted from the readings of the coil.

[Slaydog]

Great point - thank you, when shorted the meter reads 0.5 so subtracting that puts the primary in range and secondary very slightly over so I guess the coil is actually ok…

[Robsey]

Hall Sensor Testing -

Has anyone ever tested this theory.
I read this a while back and thought - that looks useful.

https://www.thesamba.com/vw/forum/viewt ... ?p=8798938

UPDATE:-
There is a video link that used to work, but I couldn't get it to work today when I tried.
Sorted - click on the word "link' under the youtube image. Not on the image itself.