2001 Monte Carlo SS 3.8 L Ram fine day before went out next day no power only thing on is the cigarette lighter and when the keys on I get check engine light no interior lights no dash lights no start no nothing need help please new member thanks in advance

 

Age of the battery / current battery voltage / last time it was load tested?

 

batteries about 3 years old was tested 2 days before this happened and it's showing 12.4 volts

 

Not to beat a dead horse, but when you say tested do you mean actually connected to a load tester or just measuring surface voltage? Ive just seen a lot of folks in the past claim to have "tested" it when their test was just a simple dvom across the terminals and it was actually down a cell or two when load was applied.

If we're certain the battery is good, then the next step is to break out the meter and start spot checking along the circuit to find out where you lose it (as clearly some systems are working if you've got a check engine light). I think the lack of interior lights is a good place to start - its a circuit you can easily switch on / off with lots of accessible connectors to measure at. Id probably start at the interior fuse box and work from there.

 

The battery was checked at AutoZone on a load meter and the only things that actually work is the check engine light the fans for the AC and the temperature and mileage readout above the windshield no headlights no dash lights other than the check engine and no kind of cranking at all

 

Do you own a multimeter/ know how to use one?

As you've got some systems functional, but not others, my next step would be to trace a circuit to find out where you lose power. As it happened all at once, I'd bet it won't matter what circuit you pick - they probably all have the same root cause failure spot (a main power wire came off, chewed through by mice, etc).


You can either start at the good end of a circuit (battery) and work towards the device with no power, checking voltage at each electrical junction. Or you can do the reverse - start at the device with no power and work upstream until you get power again. What youre looking for is the point where it goes from good to bad (or vice versa) to find out what is abnormal between those two points.


There is the remote possibility its a ground issue instead, but there are a ton of grounds in the car, so the chances of one corroded ground point / one ground fell off wiping that many systems out is pretty low. Its easy to confirm at whatever circuit you decide to trace - you can simply check for resistance to the body on the ground wire. If that comes back with a very small ohm reading, then you know its 12v that its missing.