About a week ago I go out to the truck to find what i thought I was a near dead battery. Started to crank and then gave out. Jumped her and started right up. Suspected I left something on. Drover her and recharged. Next day I go to start her again and....nothing completely dead. Suspected battery drain and was going to let the mechanic sort it out so I let her sit for a few days and tried jumping her today....started right up charged her then shut her off tried to start again and totally dead again....how in 10 seconds? Tested battery terminals put out 13 volts. Tested the wires just past the terminal.....1.5 volts...WHAT! Turned out over time even with the bolts tightened as far as they'd go, the ground wire clip had just spread open...loosened the bolt crimped the circle down a bit with water pump pliers and tapped her back in with a hammer. tightened the bolt back down and she started right back up. Simple thing to check for someone who might think they have a battery drain. Good luck all.

 

Very nice, thank you.

 

Don't have the know-how to give back very often but I'll try haha

 

You make a very good point, large voltage drop can happen right at the connector or anywhere along the path. And they add up, so a little on the battery terminal plus some from the frame ground, and pretty soon you're talking real volts. Since starter draws about 300 amps for a moment, even a tiny loss is magnified.