Blindspot monitoring frequently not working.

[Frenzy]

I would still test the batteries myself for peace of mind. Multimeters are cheap and useful to have around and it only takes a few minutes to do. It could possibly be the main battery also.

Got the truck back on Friday, said they charged the main battery and all is good. I asked why they didn't do that when they changed out the aux battery and they said it had checked good at that time....time will tell I spose