2017 Jeep Compass Battery issue
 

does anyone know if a dead auxiliary battery will kill a brand new main battery ?

A bad second battery will drain the number one battery.

them damn dodge service advisors told me the main battery would charge the aux battery so I didn’t need to replace the aux just the main one... Now I have a dead Jeep until I’m able to take back the big battery and go buy a secondary

OMG !!!!! This is B.S. Call the complaint Department and put in a formal complaint...
Mite have to change dealers or find a better local shop..

yeaaaaaaaaaaaah... if it's under warranty that's one thing but if not, stay awaaaaaay from the dealerships.