Radiator Fan stuck on Hi and A/C not working after batter disconnected 2014 Tahoe - Not Temp Sensor or Thermostat

[petethepug]

Pull the cables and load test. Is it an AGM?

 

[Foggy]

It charges at "what it needs" ... So 14V is pretty darn normal.
Really anything from 13-15V is acceptable as long as the battery
is taking a charge and it starts normal

 

[j91z28d1]

how old is this battery? if it load tests OK, it makes me wonder if the battery cables are iffy and moving them around has cause it more than anything else. they seem to corroded from the inside out. looking great but causing issues. these do act funny over battery stuff. tons of threads about it.


also check the cables are proper tight. like you can't move them with 2 and trying hard. they do not do well with snug terminals.

 

[GollyZ]

Psssst. When your fans are stuck on, go into your TCM and see what it thinks the coolant temp is.

 

[Nutro]

Does the TCM control the fan operation?

 

[j91z28d1]

Does the TCM control the fan operation?

from the wiring diagram the ecm controls the cooling fan relays.

now the tcm might be able to request the ecm turn the fans on if the tranny temp is high. that's possibly but I don't know if it does or how you'd test it.