I'm sorry if this isn't the forum for this question... I have used these forums for my truck in the past, and had good luck... so I'm simply returning to where I have had luck.

I have a 2012 F150 Lariat (5.0) that keeps draining the battery overnight. I've replaced the battery twice now, over the past 2 years, and have come to the conclusion that it must be parasitic draw... no way my luck is THAT bad, that I keep getting "bad batteries"

I purchased a Multimeter ( ) from Amazon, but there isn't much that I can find in the way of project-specific how-to. You definitely need to have a background in electrical work to understand the dial and all the terminology... and the instruction manual that comes with it might as well be written in Greek.

I just want to use it to test my parasitic draw and find the problem so I can stop carpooling to work every day

I found that seems to do a good job explaining what to do... but his device is much different from mine, and I can't figure out how I'm supposed to set my device differently in order to accomplish the same thing. (For example, his wheel has a "10" he turns to... mine... does not)

Can anyone help me out?

 

Instructions for amperage measurements. (Do not try to measure voltages with red lead in amperage positions).

Put black lead to com (common). Put red lead to 10A (good for up to 10 amps). Place dial switch to A. Meter will read current up to 10 amps.

If reading is less than 1, setup to read milliamperes (mA). Move red lead to mA and turn switch to mA.

One mA = .001A, (1000 mA = 1.0 A)

Instructions should show how to replace an internal fuse that will blow when leads and switch are incorrectly set.

Picture shows switch in position to measure voltage. Leads would be Black to com, Red to CE to do that.

 

When the key is withdrawn from the ignition switch there is a little door that closes to block dirt and dust from getting inside to the tumblers. The door also operates a switch that lets the truck know a key is inserted. That starts up dash lights and maybe more. Mine wore out, operated intermittently, gave me trouble and was replaced. I could wiggle the key in the ignition and get dash lights and key left in ignition warning to go on and off.

2011 XLT Screw 4x4 3.5L 3:55LS

 

Just go buy a DC amp clamp, clamp it over the power lead off the battery and measure the draw. If after a timeout period for you truck specifics the draw does not go down, start pulling fuses until the draw drops to almost nothing, then troubleshoot that circuit.
https://www.homedepot.com/p/Klein-To...L390/312649921

 

mine did that a few months after i purchased it. took it to 2 dealers and got a new battery. No one could find the issue. Then i noticed one night that my truck was locked but there was a glow coming from inside, it was the cluster lit up. It wasnt turning off. Down at the bottom where it showed what trans position i was in, P,D,R, etc.. it wasnt showing that it was in park. i put my key in and started it, then pulled the selector back and put it back in park and the P switched to amber. As soon as i let off the handle the amber light went off the P. So i knew it had to be related to the shifter somehow. After doing some reading i found this part, took of the cover next to the shifer and replaced this switch.
https://www.ebay.com/itm/303135581873

The P lights up when i put it in park now. and the cluster lights turn off after its locked. Maybe this will help you guys...

 

The clamp on amp meter referred to a few posts above is for measuring larger current than a parasitic draw. Maximum resolution of it is 100 milliamps. The instrument you already have can find smaller problems.

 

His battery is going dead overnight, he has a 10 am draw problem, not .1 amp
draw problem.

 

Pretty sure this meter won’t measure DC current with the clamp. That’s a CT clamp not a Hall Effect clamp. This meter will measure dc current, however the leads will need to be used

 

Klein Tools CL390 is an automatically ranging true root mean squared (TRMS) digital clamp meter. It measures AC/DC current and NCVT via the clamp,

 

AC/DC voltage, DC microamps, resistance, continuity, frequency, capacitance, and diodes via test leads, and temperature via a thermocouple probe. It features a high visibility, reverse contrast LCD display that optimizes view ability both in dark or bright ambient lighting.