Help wiring a new voltmeter. Can I use the wires from the cigarette lighter / powerpoint harness?

Not going to happen with that device.t would probably fry.

 

Oh for sure. It's not built for that. But my point is that I figured I could use it to measure the draw from some of the lights I am wanting to install. I would imagine it should be able to handle that without issue.

 

Second one is correct. 1st one won't work since the current will bypass the meter straight to ground.

 

Gotcha. And yea, that's what I thought you meant, but just wanted to triple check. Thanks so much for your help with this! Really awesome to find people in here who understand this stuff far better than I do. I'm delighted to be learning!

 

It's how you get to be in the know. I've had help from others so I'm happy to help where I can.

 

I got one of these for each car in my household - except mine cause I have dual batteries and have a dual voltage readout (which I haven't installed yet). Anyhow, they are simple and effective. The quirk about them is that when you plug in a device, it will switch back and forth between voltage and the amp output - very annoying as I wish it would only show the voltage reading.

 

Yea, I saw those and thought about them, but am just trying to install something that's a little more permanent to my system. So I've got the voltmeter / ammeter already going (as you can see from the previous posts) and I've actually ordered a dual USB charger. My plan is to wire the ammeter to the dual USB charger so that it shows me the load being drawn from whatever I install. I mostly just wanted the voltmeter for the overall battery reading, but since I saw the ammeter as a bonus, figured that I'd use it for something while I was at it.

Anyway, I do like the cig chargers, but am specifically trying to remove those powerpoints from the car since I feel like the cig adapter should have been done away with a decade or longer ago.

 

I was eyeballing a contraption like this to replace my cig lighter plug as well. This thread would make things much more "express" for me when it comes time to me doing it. So I like this thread.

 

So I still don't have the new USB device that I'm going to install yet, but I wired up the ammeter (the load on the voltmeter) in the way that you guys told me to and hooked it up to my existing powerpoint. It works really well. Tested it just hooked up to the powerpoint and it would read about 0.01 amps. I plugged in my inverter and that took it to about 0.42 amps. Then plugged a USB into the inverter and it jumped up to about 0.89 amps. So looks like it works well. Excited to see it hooked up for real. Thanks again for all of the great help with this small part of my project!