206 battery light problem

Hello everyone. My car is a 2001 model gasoline LPG 206. This problem occurred after a mechanic replaced the fuel injector and ignition coil. My car's battery light only comes on when I press on the gas. If the air conditioner is on, it turns off. The light goes off when I release the gas. The air conditioner turns on again. When the light comes on, I had a measurement, albeit difficult, and the voltage of the dynamo increases up to 15.8 volts. But this happened after the repair. I don't know if it's because they wiped every part of the engine with WD40. The electricians say that even if it was from the dynamo, it wouldn't be like this. The V-belt was changed, the battery was changed, but there was no improvement. Maybe someone has information or has experienced this. Thanks in advance for your help.

I haven't received any answers, but I think I've found the problem. If the vehicle is run directly on gasoline and not switched to LPG, the problem goes away. It starts again when the LPG is switched to LPG. I think I'll look for the problem in the LPG system.

Unfortunately, it's only started doing this with gasoline. Does anyone have any ideas? I'm looking forward to your help.

Sir, that leaves the alternator, or alternator. Don't waste your time searching for the problem elsewhere. If you find a professional, measure the voltage while driving, or have one done. When there's a problem with the alternator, it can sometimes work properly and sometimes produce too little or too much voltage.

First of all, thank you for your answer. I will check it as soon as possible.

But I can't be sure. I just came 50 km. The air conditioner is on, it hasn't failed even once. I also think there might be a chassis problem.