Little blinking red light on sleeper ac control panel

I have a 2006 Volvo VNL and on the ac control panel in the sleeper there's a blinking red light when the truck is not running. Not sure if it's doing it while the truck's running havn't checked that yet. I just got this truck not too long ago and havn't used it to pull anything yet still working on it to get it in trustworthy condition if that's even possible lol so there wasn't any power going to the panel when I got it found out that the fuse had been pulled so put the fuse back in and lights on panel came back on and then shortly after the blinking red light.. I've been having electrical issues with this truck so there's that.. Anyways if any of you have any idea's on what it is I'd appreciate your input. Thanks.

 

Fantastic.. I have the battery charger hooked up at this time so there should be constant voltage going so but I'm not sure one of the battery's isn't bad.. I bought 4 new batteries not too long ago but they'be been drained down to nothing a couple of times, but I've charged them back up although there's at least one or 2 that went bad through that..

 

Were are those located\?

 

the ground locations that is?

 

side skirts, battery box deal is under drivers side door area. I looked behind there for grounds didn't find any but i'll look again. not sure if the lights are dimming or not while cranking, i havn't really noticed anyways. seems to crank at a normal rate. i did clean the battery post recently and that seemed to make a difference on the crank speed when starting. im pretty sure your right on the money with the grounds needing to be cleaned up just need to figure out exactly were they are located.