a week ago i was driving in really hot weather.
i turned the aircon and it sounded like there was a burning sparking noise coming from the ecu so i turned the aircon off and it never made the noise again. next day car was in the garage on jack stands and i tried to start it, it just didnt start and all electrics went off, no lights no interior lights nothing worked.

then yesterday it was hot again i was driving around and noticed at lights the revs were dropping really low especially when i just stopped, then it would jump back up to normal revs and idle properly.
its been running between N and O on the temp gauge the last few days.

then today i drove to the mechanics to get a quote for turbo oil return line fitting installed and when i went to start it, it went to turn over and just stopped all the power went dead, not one electrical thing working, tried again still didnt, got a battery and leads from the mechanic and it took a few seconds for it to start. then ran fine till i went to start it again before and it started real slow then went fine, it reset the trip computer and ecu and head unit, so power failed.
then tonight everytime i turned the car off i had to start it with the portable jumpstart thing, otherwise it wouldnt start.


I do have the intercooler and transmission oil cooler installed infront of the radiator. and all the cooler piping is run so, so currently its sucking in air from the hot side of the engine bay.


while i was at the mechanics, he tested it with the multimeter and it was only doing about 12 volts while running.
my question is could all these troubles be caused by the alternator if its the alternator?

does the alternator usually die in hot weather?

if its only 12v while running, you either have something causing a big voltage drop. (like a really clagged battery or a low resistance short somewhere) or your alternator is not putting out what it should be..

in my experience, you should be looking at between 13 and 14v when the cars running.. (13.3ish is normal)

as for the heat/alternator issue.. if it has worn out brushes.. odd things can happen like that.

on the Voltage thing, 13.3 Volts is s**t, it should be around 13.8-14.4 at idle