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tim-w avatar image
tim-w asked

BMV-712S Showing voltage but no amps.

I just installed a BMV-712 Smart into a Jayco Melbourne 24L. Upon install, it is showing only Voltage readings. If I turn devices on, the voltage falls. If I turn them back off, it climbs backup. If I hook up to 120V, it shows 13.52v. However, it is not showing any amps. This stays at 0amps.


The system is connected to a Duralast 27DC and a Duralast 24MD-DL that are in parallel.

I tried a plethora of sources and videos, but still could not figure out exactly what the issue could be.

Should the second negative wire (chassis ground) of the 24MD-DL battery be connected to the shunt? or because they are in parallel, connected to the Negative of the 27DC?

If I do need the shunt on the other side... is it better to have the shunt closer to the ground? The two compartments are about 5 feet apart as a wire would travel.
wiring.jpg


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1 Answer
JohnC avatar image
JohnC answered ·

Hi @Tim W

What you've done here is bypassed the shunt with that Chassis Ground. It must be carrying the current you want to measure, with your loads attached to ground as well (you don't show this in your wiring).

Move it to the Load side of the shunt.

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tim-w avatar image tim-w commented ·

A couple of follow ups:


The two compartments are about 5' apart.

I am trying to figure out the best place for the shunt... Guessing in the 24MD-DL compartment with Battery connected to the shunt. Would it look like this?wiring2.jpg


Would I hook the 2nd red wire to 27DC Positive and then to B2? Or could I reserve that for that starter motor?

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