Won't Start/Electrical Short?

[MaraudrManchild]

Hey Guys,

Been a Lurker here for awhile and could use some help. Back in August drove my Marauder for about an hour then stopped at a gas station for all of 40 seconds went to start back up, got one click and all interior power cut out. Car wouldn't start even with a jump. Got a new battery was good for about 3 months then the same thing happened. Warrantied same battery (bad cell) same results with warrantied battery.

I can charge the battery and get same results interior lights kick on, all the normal chimes, fuel pump kicks, once I actually go to crank 1 click and everything cuts out. Since then I have replaced the starter, tested continuity with a voltage meter between starter and positive battery cable. I tested all the fuses and verified the major grounds (to the best of my ability). I test continuity between the block and the ground screw on the body near the battery. To me ground is ground and if I get a good reading between that screw and the block/frame ground is present to both block and frame (please correct me if that is the wrong thought). I also verified resistance/continuity between alternator and negative battery cable along with that ground too.

When I charge the battery I get it to around 12.8v but it will drop to about 12.5-12.7 after I try that initial start. I have seen many posts about no crank no start related to fractured harness wires or a pats issue but all of those seem to retain interior power without even an effort to start (no click). I lose all power and it does not seem to come back unless I disconnect the battery and charge a bit. In my mind a bad relay would yield no click, bad alternator I would start and not retain charge, starter is new motorcraft reman so that's out. Maybe ignition switch?

The battery is a motor craft from my local Ford dealer. Hopefully something stupid I'm missing. Not really sure where to go from here. I appreciate any help/feedback and sorry for the chapter book length explanation.

[JohnnyCashMerc]

I was having similar issues with a crown vic I had and went through 2 batteries. Even though all answers didn't point to the alternator, I just went to the junkyard and got an alternator to see if it would help and it totally fixed the issue. Hope that helps. Good luck man.

[fastblackmerc]

Test for voltage drop when starting. As these cable age they can get corroded internally.

https://www.batteryskills.com/how-to...ables-are-bad/

Also check all the ground (-) points, remove the cable(s) and clean the mounting surface and cable ends unit they are shiny.

[MaraudrManchild]

Well stupidity strikes again. I went to do the voltage drop test and noticed the cables going to the positive terminal had some slop and could move around a bit (it is not a crimp style but the one with the plate and 2 bolts that secure cables to the terminal). I snugged them tight as I could had the wife turn it over while I checked voltage and she started up. I've been able to start it a few times since. I still find it odd that it did it once then didn't show itself for months and then happened again with permanent results until now, I know I also got good resistance readings between the starter and terminal itself, as well as the fuse box cable and terminal before I noticed the loose cables. Either way it runs so we will see how it plays out. Thanks for the tips guys!