Nick, I'm not familiar with your particular multi-meter, but to me, it looks like in the pictures in posts #39 and #40 the multi-meter is set to 2000m DCV, not 200m DCA.
DCV stands for Volts (it measures Direct Current Voltage)
DCA stands for Amperes (it measures Direct Current Current)
OK. This shows that there is current flowing through the system even though the battery is off...it shows that there is a 'parasitic drain'.
EDIT: Hang on, from looking at that picture, it appears you have not removed the negative battery cable and installed the multi-meter in series between the batter cable terminal and the neg battery post...
Yeah. I had just realized what I had done before the last picture, I had it on opposites because of how confusing this meter is, the dot on the dial is too small so I got it switched around. I hate this meter, my dad has his nice fluke meter with him and he won't be home until this weekend. So this crappy harbor freight thing will have to do
Nick, in post #45, where are you touching the red lead from the multimeter? I can see in the picture that the black lead is touching the neg battery post...or is that the positive battery post...
The correct way to connect the multimeter is to remove the neg battery cable from the neg battery post and connect one multimeter lead to the neg battery post and the other multimeter lead to the now removed terminal of the neg battery cable. Make sense?
This has been my setup the whole time. Sorry I didn't get the big picture. But for some reason my reading went to zero. This is making me super mad!!!!
Take off the negative lead. Keep the positive lead attached to the positive terminal of the battery.
After you remove the negative lead, then:
connect one multimeter lead to the disconnected neg battery cable
connect the other lead to the neg terminal of the battery
With the multimeter set to measure 200m DCA, what value reading does it give you?
FWIW you're in good company... Niels Bohr (the genius Danish physicist) would understand...
"An expert is a man who has made all the mistakes that can be made in a very narrow field."
Niels Bohr
So what's next? Another HF multimeter?
If so, this time before you connect it, set it first to '10 A' (this is right below the 200m DCA position). The '10 A' setting can handle 2 orders of magnitude more current than the 200m DCA position. Also note that to use the '10 A' setting, the red lead must connect to the multimeter in it's own, dedicated slot...
Now that you know how to correctly install it, what reading do you get from the new HF multimeter when it is set to '10 A'
THat's why I warned you about using the high amp setting first, then the low one. It looks like your low side isn't fused, so yep-you fried the meter.
But you have confirmed you have a large parasitic draw. Now, you need to find it. Go buy another $2.99 meter (actually buy 4 of them). The first thing I would do is COMPLETELY disconnect the alarm. Se if you still have a parasitic drain. If yes, then you need to check each circuit. Once you know what circuit it's in, look at the wire diagram and check everything in the circuit-wires, fixtures etc.
Regarding how to measure, turn everything off in the truck. Close all the doors etc. Leave the + attached, but disconnect the negative. Then measure between the (-) battery terminal and any ground with your meter set on 10A. Confirm the draw is less than 200mA before you go to low range. It looks like low range isn't fused. Don't feel bad, we've all blown fuses measuring amps.
