How to check for battery drain

[Mark_88]

I've just installed a fairly new battery in my Ranger about three weeks ago. It started fine when I put it in and left it for three weeks. Went to start it yesterday and there was no crank at all. The battery now shows about 8.5 Volts so it shouldn't be a problem to boost it.

My concern is that although I left it sit for three weeks it should still crank. Is there a way to test to see if there is a drain on the battery?

The last battery I had in it was completely dead and would not even show anything on the voltmeter even with the lowest setting. This battery was made in 2009 and seemed to have plenty of power...

 

[RangerSVT]

Take an old test light (not digital meter) and connect the alligator clamp to positive battery post. Then start testing at your fuse box on the fuses (you will need to pull the fuse and test the circuit side, not the battery side). If the test light lights up, you have a drain.
SVT

 

[Sasquatch_Ryda]

Get yourself a DVOM (digital meter) and disconnect your positive battery terminal. Connect the DVOM in line between the positive cable and the positive terminal on the battery (set to DC mA). Make sure all accessories are off, doors are closed and keys are out of the ignition. If you get a reading of anything higher than 0.05amps you have a draw that will kill your battery. Start removing fuses until the draw goes away. The draw will be in the circuit that you removed the fuse for.

 

[Mark_88]

Thanks guys...Earl sent me something similar to try also and I will have a go at that...might be the lighter that I rigged up last year because that was all that I changed...

 

[Mark_88]

Update...wasn't a drain per say, it was the way I had the fuel pump wired...I thought it was in an accessory or "key on only" fuse...but I somehow hooked it into my lamp wiring...that is always on...

Problem fixed...thanks again for the great info though...