So Everytime we turn our Chevy Suburban 2002 off . It blows the TBC fuse. Why is it doing this?

 

https://www.gmtruckclub.com/threads/...-drain.137050/

Try this for hopefully some help.

 

The TBC fuse supplies power to the BCM (one of several), the remote control door lock receiver (if equipped with keyless entry), the headlamp switch and headlamp dimmer switch (part of the multifunction switch on the column).

One way to determine if it’s the headlights is to remove the headlamp relay in the under hood fuse block and cycle the key (or if driving is necessary, go for a short drive) to see if it blows again.

If it doesn’t blow, reinstall the relay and repeat the test, only this time remove the individual fuses for the left and right headlights one at a time. If removing either fuse prevents the TBC from blowing, the problem is isolated to that circuit.

If it still blows with the relay removed, the problem is isolated to the BCM, door lock receiver, or wiring harness.

Also, mice are known to nest under the fuse block. Even if there’s no indication of nesting, remove the fuse block lower cover/shroud to inspect. You will have to remove the fender to firewall brace to remove the fuse block lower cover.