2003 Silverado ABS Parking brake light and battery

Hi everyone. I have been having this issue
which is the same exact issue as this user
posted a very long time ago and then
throughout the ears has been updating but I
haven’t seen anything recently and it’s very
frustrating. It has been going on for about a
year now and I can’t pinpoint what could be
happening yet I only drive my truck on the
weekends and I have a bit of a mobility issue,
so I’m worried that I will get stranded
somewhere or stuck at home because of it

Basically, the ABS and parking brake light will
come on at random times with the alarm and
then either stay on the entire time I’m driving
or shut off and come back on randomly and
more recently. My battery gauge will go all the
way down like there’s no battery connection
the radio will shut off the air conditioning will
not be cooling at the same time and then
maybe a minute or two later it comes back up
to normal again, and then on and off
sporadically

We put a computer on it a while back and it
was giving codes for the EBCM losing
connection which I have seen others talk
about so I don’t know if it’s just that module or
something in the wiring or something behind
the dash as stated by the other user with the
link I posted below. C0291 and U1041 are the
codes that popped.

I don’t have the ability to work on my truck
myself anymore so I have to have someone
do it for me but as you know this can be tricky
to diagnose so I’m really at a loss here I’m not
sure what to do. Any sort of guidance or help
would be much appreciated if that’s even
possible.