Digital Volt/ammeter setup question

[ringo]

I know a few people have installed the digital ammeters that come with a current shunt.

I have just installed mine and am getting no reading for Amps. The reason for this is because I have connected my meter to the end of a 3m cable which is simply not up to the job when dealing with such low voltages (low mV).

So my question is, what length of cable (and what diameter of wire) have people been using to get a meaningful reading from the current shunt?

Thanks in advance,

Ringo

[bigherb]

I have just installed mine and am getting no reading for Amps. The reason for this is because I have connected my meter to the end of a 3m cable which is simply not up to the job when dealing with such low voltages (low mV).

Doubt if that is the problem. It is only a voltage signal going up the cables no load so it doesn't need to be heavy cable, it only measures the voltage between the two cables.
Check the two cables from the shunt for continuity, is the shunt the correct amperage if it is too high it won't always register low amperage.

[nicq]

What wire have you fitted the shunt in

[ringo]

Hmm. The reason I suspected it was the cable was because it works if I connect the meter next to the battery/shunt. I'll check the continuity of the cable - good idea.
The shunt is in series with the ground - as per instructions and also stops a massive bit of live metal wallowing around

[ninja.turtle007]

I have a similar problem. Mine didn't come with instructions though. After some head scratching I had it working perfectly on the bench. I fitted in the van with the gauge about 1.6m away from the the shunt and the reading was 50% lower than it should be. I tried to adjust the pot on the back and it went to zero. I moved it closer the shunt and it worked again. I moved it back to the original position and nothing. After some fiddling it's now stuck showing 50A.

Not sure what I have done, maybe I damaged it by not using a separate power supply. But again it was working fine on the bench without using a separate power supply.

[Oldiebut goodie]

I am sure that in the guff that came with the one that I tried it said that it wouldn't work correctly without using a separate power supply. It needed a reference voltage that was different to that of the current carrying cable. Mine died before fitting so didn't get to test it for long and wasn't going to waste money on another one.

[ninja.turtle007]

I am sure that in the guff that came with the one that I tried it said that it wouldn't work correctly without using a separate power supply. It needed a reference voltage that was different to that of the current carrying cable. Mine died before fitting so didn't get to test it for long and wasn't going to waste money on another one.

The bench voltages I used were variable and the volts and amps followed fluctuations equally.

I'm probably going to try another unit but I am considering the the quality being an issue.

[CovKid]

I've got the volt/temperature/clock version. It works perfectly but yes you need a constant supply even on that with the unit having a separate wire to read actual volts. I hooked the volt sensor into the upgraded cable I added earlier this year to dash for headlights to get an accurate reading but used the low-level 12v dash supply to power it.