Electrical issues it was only showing around 11V.?

Thought it was another bad alternator so we warrantied it out and replaced it again and still the same issues. Took it to auto zone and had them test it and it shows voltage regulation failed. When the cars is running and I test with the multimeter at the battery, it tests at almost 19 V which I know is way too much. I took the wipers and cowl off to visually inspect the PCM and I don’t see any melted wires, corroded plugs, or anything else. I am just stumped... And still without transportation. I have gone through and tested the fuses with a multimeter and they all test fine but I did go ahead and replace #f1.18 and #f2.20 just to be safe. Desperately seeking a solution. Thank you so much!

If the key is on (engine not running), everything seems like it’s going to work fine. Interior lights work, door chime, door locks, etc, but the minute you start the engine, everything shuts off and the battery light comes on. I ran the codes about a week ago and the only code that it showed was P0563. I keep the battery disconnected since there’s such high voltage; I don’t want to ruin another battery.

A few months ago, my car started having some weird electrical issues, which I assumed was due to my alternator since I had it tested and it was only showing around 11V. Flash forward, I had a new alternator put on and also got a new battery. The issues are still there and even worse. Battery is completely draining to the point that I’ve had to replace it 3 times in 6 months.

However, we took the alternator back off the car (no easy task) and took it to be bench tested. It tested just fine. We fully charged the battery up and then put the alternator back on and it was showing no signs of draining. Until we started the car. Within minutes, all of my dash lights and gauges went off, all interior lights went off, and windows, door locks, etc, were inoperable. The only light that was on the dash at that time was the battery light but before everything went off, it was cycling between the check engine and check transmission.

After the suggestions of someone on my last post, we thought it was another bad alternator so we warrantied it out and replaced it again and still the same issues. Took it to AutoZone and had them test it and it shows voltage regulation failed. When the cars is running and I test with the multimeter at the battery, it tests at almost 19 V which I know is way too much. I took the wipers and cowl off to visually inspect the PCM and I don’t see any melted wires, corroded plugs, or anything else. I am just stumped. And still without transportation. I have gone through and tested the fuses with a multimeter, and they all test fine but I did go ahead and replace #f1.18 and #f2.20 just to be safe

I am at a complete loss on what to do. I can’t afford to take it to a mechanic and pay for hours of time for them to search out the problem. I’m struggling to get back and forth to work as this is my only mode of transportation. It is also the only means of transportation for getting my elderly mother around so I desperately need my car fixed. Please help give me some ideas of what to check. Thank you!

I have rechecked the voltage at the battery when idling multiple times. I did it again a short while ago and it shows 18.8 volts. This is the 3rd new alternator.

I borrowed a more advanced OBDII reader and when I selected the option to reset the battery monitoring system; I got a message stating that my car is not capable of that function. My guess is that it is too old, being a 2005. However, it did let me go through and reset the codes, etc, and all of the codes in the various systems had something to do with high voltage. I reset everything and the car ran beautifully for about an hour. I let it sit and idle for quite some time and then drove it around town for a bit. Everything was great and when I tested voltage at the battery with the car running, it was testing around 14.6 volts and then I shut it off and went in the house for about 30 minutes and when I came back out, it was back to the same old thing... Lights, dash, and all other accessory functions were nonoperational and the voltage was showing around 18V when tested at the battery but it wouldn’t let me reset any of the codes or systems this time. To avoid ruining another battery and further damaging the system with such high voltage, I just unhooked the battery again and walked away. I am just at a complete loss.

So when you say that there’s no programming needed are you referring to something other than what is being referenced in the screenshot that I attached?