New and Improved Vehicles

So last year my 2015 Jeep Cherokee died one below Zero day - battery just stoned itself overnight . OR SO I THOUGHT - it seems little signs showed up over a couple years with some features not working in dash . Stop / Start and odd times of warning lights - original battery from 2015 until 2025 - yet battery voltage varied which created problems 
  Other day went to start my 2010 GMC work truck - battery lit dash lights but when turning key nothing . cycled key on and off a few times and it started then died .
 Put charger on it to try to start , no go / Let charge a couple hours at 10 amps / Nothing 
Changed battery with one I had in shop - engine started - died in about 10 seconds 
 Charged battery couple hours - same 10 second run . After charging overnight started next day but dash gauges fluttering on and off and rough running engine .
 Checked output of alternator and was in 13 volt area 
Took battery out of other plow truck (2000 GMC) installed and truck started but dash fluctuated on and off on instruments .
   Seems the Alternator charge rate is set by the ECU now and unit has 4 wires - 2 to regulate and 2 to tell the ECU what to do about rest of charging system .
 Seems if voltage is not high enough ECU shuts down the engine , if battery voltage is low it will not allow alternator output to rise so control engine or dash , radio or other accessories - battery charger with High Amp Start cycle will not overcome ECU .
   So yesterday 2 new batteries as year old ones had internal problem - then after they were installed dash still flickered so new Alternator (160 Amp unit)and it runs , starts and gauges read steady .

I bought a new Chev truck last year. I drove it home off the show room floor. The next day it would not start. An intermittent problem. After a lot of "We can't find the problem" It spent a few days at the dealer, they put a new battery in it. It's been fine for a year.

Well thought the problems were solved  WRONG 
Went to drop off a tire for skid loader 5 miles from here ?
1/4 mile from house gauges started acting weird , tac fluctuated , speedometer from 0 to 50 MPH and then to 30 - then ) back to 40 
 Gas gauge 1/2 tank to empty . 60 PSI oil pressure to 0 and all over between . 
Stepped it down - would not shift up but stepping down hard back shifted - then truck bucked - sped up and then slow down jerking both ways . 
 So made it to tire shop and back but a adventure of where will it stop completely - Seems I am getting to hate anything that doesn't have a distributor and simple carburetor - the GMC has 34,000 miles on it when I bought it in February - ran OK but now it's PROBLEMS ..   

Biggest issue of the simpler is the parts are being discontinued to force capitulation.  

A 2010 GMC truck has a basic version of a battery management system (BMS), but it's referred to by GM as the "Electrical Power Management" (EPM) system. While it lacks the advanced features found in modern electric vehicles, it is still a computer-controlled system that monitors and controls the charging system. 

• Voltage regulation: The EPM uses a sensor on the battery's negative terminal to monitor its state of charge. The system can adjust the alternator's voltage output to optimize the charging process, reducing engine load and improving fuel economy when the battery is sufficiently charged.

Edited by steve(ill) - 5 hours 46 minutes ago at 8:34am

part of this is due to the use of the Internet.. LOTS of info get published these days.. Didnt see that 30 years ago..... US makes 10 MILLION cars and trucks a year and what you see on the internet is the 1000 guys that have PROBLEMS.... Many trucks run for10- 15 years or more and never have a MAJOR problem..