Hall Effect sensor tester

[DanHoug]

here's a nifty little tester that will tell you if the Hall Effect sensor in your distributor is functioning. this can be done on the bench or with the dist installed in the engine. the schematic is not mine, robbed from the BMW airhead forums as they use the same Hall sensor in the 'BMW Beancan'. but this particular schematic is well designed and has a low current draw that will not burn out the Hall sensor. it's simple... just plug into the distributor and turn the shaft. it is self powered so if the sensor is good, the LED lights and extinguishes as the vane windows block the sensor.

i assembled the unit in a pen barrel and it is a great thing to have in the road box for troubleshooting.

Tricky Bits:
- the VW distributor plug is part number: 052905327 they are available on eBay but i have a stash of my own.

- the plug comes without pins. it uses an open barrel pin, requiring an open barrel crimper and the style from TE Connectivity is called "Connector socket 15-20AWG Crimp" MFG pn 925590-2. Digikey has them, PN A107135CT-ND. one CAN fold the flags over onto the wire with a pliers if you don't have the open barrel crimper.

- the schematic references a 12 volt diode and you MUST use a 12 volt LED or a regular LED with a dropping resistor. if you use a regular LED without a dropping resistor, you WILL ruin your Hall sensor!!!

- the 10k resistor in the schematic is a 'pull up' resistor to bias the sensor with some voltage. this was added by the author because spec sheets on Hall sensors request it and i like this attention to detail. it is NOT a dropping resistor for the LED!!!

here it is in action:

Link

_________________
-dan

He who knows he knows, doesn't know. But he who knows he doesn't know, knows.

'87 Westy, ratty but drive anywhere.
'89 Westy, gorgeous but hasn't been gone thru to drive anywhere.

[Gruppe B]

You know that many of us would buy this if it were available..

[DanHoug]

yah but... now you have the Secret to the Sauce so you can roll yer own!

it would sorta terrify me to a) charge what i think my spare time is worth as these are a little fiddly to make, and b) try to sell something that people wouldn't gripe about.

much prefer to provide detailed enough info that folks can just do it themselves as the construction is dirt simple if you have rudimentary soldering skills (or want to learn).
_________________
-dan

He who knows he knows, doesn't know. But he who knows he doesn't know, knows.

'87 Westy, ratty but drive anywhere.
'89 Westy, gorgeous but hasn't been gone thru to drive anywhere.

[Vanagon Nut]

I just went outside to check my parts collection. The mk3 2.0 ABA engine uses the same looking distributor connector as the 2.1 WBX. Maybe other older vw's do as well?

Neil.
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1981 Westy air cooled to 15º ABA swap: http://tinyurl.com/y9n4xob8

50º ABA Swap in to '88 Westy: http://tinyurl.com/yap5hpwt

Vanagon VAG GAS engine swap Google Group:
https://tinyurl.com/2f24rmh

VE7TBN

[DanHoug]

i think the connector is used on a large number of VW, Audi, BMW, Volvo, Saab, Porsche, etc Hall distributors. the key in shopping for them is to NOT buy the similar looking "EV TPS" connector.

i bought a bag of 25 of the genuine VW ones that were being cleared out. eBay vendors list both VW and aftermarket ones.
_________________
-dan

He who knows he knows, doesn't know. But he who knows he doesn't know, knows.

'87 Westy, ratty but drive anywhere.
'89 Westy, gorgeous but hasn't been gone thru to drive anywhere.

[zimflux]

Is there an updated part number for the plug? Seems mine is different than the later models...

https://photos.app.goo.gl/kN9i1apKUpAPJyXSA

Thanks.
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84 1.9 Westy

[DanHoug]

the contacts you show are the same style, it just seems to be missing the wire retention bail and housing. just guessing but the PN i listed would possibly work.
_________________
-dan

He who knows he knows, doesn't know. But he who knows he doesn't know, knows.

'87 Westy, ratty but drive anywhere.
'89 Westy, gorgeous but hasn't been gone thru to drive anywhere.