Amploc Key 100 incorrect reading on GEA 24

[storkeye]

Hi,

I am using an Amploc Key 100 hall effect sensor to read amps to/from the battery. According to the Amploc manual it should read around 2.2v with 0 amps passing through it. However, the G3X is showing a sensor value of just 0.075v at 0 amps.

I have the Key 100 wired as follows:

Inner (pin 1) goes to Pin 14 on J244 GP4 +5v
Center (pin 2) goes to Pin 16 on J244 GP4 Ground
Outer (pin 3) goes to pin 15 on J244 GP4 in

I have also tried wiring the sensor to pins 30, 31 and 32 (GP5) with the same results.

I have tested continuity from the J244 connector back to the connector for the sensor and all the pins all match with no crossover, shorts or noticeable resistance. I have confirmed that +5v and Ground are correctly reading at the hall effect sensor connector.

I have carefully removed pin 15 from the connector at the GEA end and, with the J244 reconnected to the GEA, confirmed there is 2.4v correctly reading at the crimp pin.

I have been through the G3X manual several times and can't see what I've done wrong. My thinking is that if pin 15 is reading 2.2v with a test meter at the J244 plug it should show the same on the G3X, right?

Steve at Amploc has been amazing, he sent a replacement unit but that does the same thing.

All other sensors I've wired such as flap, trim and fuel sensors work as expected.

Any suggestions on what I can test next or what I may have missed would be very much appreciated.

Thank you,

Abe

 

[lr172]

I have been through the G3X manual several times and can't see what I've done wrong. My thinking is that if pin 15 is reading 2.2v with a test meter at the J244 plug it should show the same on the G3X, right?

Unless the configuration is wrong and it is adding a pull up or pull down resistor, which are typically used with resistive senders. Are you sure that you were making changes on the GP4 input?

 

[storkeye]

Unless the configuration is wrong and it is adding a pull up or pull down resistor, which are typically used with resistive senders. Are you sure that you were making changes on the GP4 input?

Yes, I double checked I was configuring the correct GP. When I disconnected the connector from the sensor the G3X system showed a Red Cross through the display which confirmed that it is seeing the sensor.

 

[mburch]

However, the G3X is showing a sensor value of just 0.075v at 0 amps.

The "Sensor Value" item here is not actually showing you that it's reading 0.075V at the GEA 24 input pin, rather that it's reading some voltage that is 0.075V higher than what it thinks the zero-current value should be. It's very common to need to adjust the "Zero Offset" value to make it read zero amps when no current flowing.

 

[storkeye]

That's got it! Thank you.

I had assumed the the first Hall Effect sensor wasn't faulty when I saw that both showed about 0.075v instead of the expected 2.2v.

However, Setting the Zero Offset correctly on both sensors revealed that the replacement sensor reads correctly and matches the readings from the multimeter.

Testing the faulty sensor the same way shows amperage drifts significantly from the multimeter as loads increase.