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Discussion Starter #1
Is there a way a continuous reading ammeter can be installed in the truck that won't be damaged by the starting amperage?
 

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2013 GMC Denali 2500 CCSB 4x4
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There exist high-current, low-resistance precision resistors for EVs to measure things like battery load and charging current (basically converts the current to a small voltage signal). They are designed to be installed inline between the battery pack and motor controller or charger, and can handle hundreds to thousands of amps. Not sure where to source one though.
 

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I would go with a DC current transducer wired to a digital process meter.
Something like this; DT Series Large Aperture DC Current Transducers | NK Technologies
Wired up to something like this; 1/32, 1/16, and 1/8 DIN Universal Input High Accuracy Controllers
These work on 24 volt control voltage - so you'd need a 12 to 24 VDC converter.

This would give you full range DC current readout. It also would not be damaged by the starting current of the starter. It also is non-intrusive, so it will not require cutting large gauge cables - you just feed the cable through the opening on the CT.

Most of the time automotive ammeters are only wired up to the alternator output, which is much less (something like ~200 amps) So positive amp readings mean the alternator is providing charge current, and negative amp readings indicate a bad alternator.

One thing to note, any device (shunt resistor or dc current transducer) is going to struggle with very low current due to turndown ratio - so a system designed to pickup 1200 amps will have a hard time reading very low current (like 50 mA)
 

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Discussion Starter #5
First, thank you for the replies, however, I'm learning that I should probably ask is there a way to hook up an ammeter that will indicate current draw exclusive of starting current. I have been experiencing parasitic draw and would like to monitor that. In trying to chase down the culprit circuit, I had a multimeter hooked up to one of the batteries negative terminal and as I was pulling fuses one by one in the box under the hood and observing the meter the amp draw did drop but not while I had a fuse pulled. I heard a click, most likely from one of the relays in the fuse block, unfortunately I couldn't identify which one, so I'm stuck until that relay dies. In the meantime if I can monitor parasitic draw, I can at least know when my batteries will be drawn down. Sorry, I thought my first question would be my solution, but after reading your detailed responses I learned that I had asked the wrong question.
 
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