No Power on my engine, dashboard, AC, Headlights, Radio.ect..ect and can’t pass emissions.

Hello. I have a 1992 Toyota Winnabago. 3VZE, V6 3.0 liter engine.

Just recently. I was having a issue where the truck would die when I was slowing down at stop signs/red lights.

Sometimes, it would completely die and I would have to put in in park and restart it. Parked it yesterday. Now it won’t start at all.

My buzzer comes on when I open the door with the key in the ignition. No other signs of life.

The Engine is brand new, (only 1000 miles on it), Headgasket, Brand new Battery, Brand new 80amp ALT fuse, Brand New MAF Sensor. 02 Sensor, Catalytic Converter, Radiator, Fuel Filter, Water Pump, Spark Plugs…ect…ect.

About 15,000$ in total Repairs and Maintence over the course of 1 year since I purchased it. It was at 192,000 miles on the old engine.

It also can’t pass emissions, Idles too high and burns to rich. Any suggestions on what to try next.

I’ve only gotten it to start by hooking cables to another car, putting the negative cable on the negative battery terminal of the truck, and hooking the positive cable directly to the screw on the 80amp Alt Fuse.

Cranks up and runs like nothing is wrong when I do that. Any suggestions on where to check next?

Update, I got it able to run without the cables once I got it started, however, my battery only reads 12.9 volts while it is running. So I’m thinking the Alternator could be bad….

Thoughts?