It's a Peterbilt 379
The turn signal flasher relay switch, on a Peterbilt 379, is located under the dashboard. The relay simply plugs in.
2007
First indication is model year. The 379 replaced the 359 in production in 1987, and was manufactured until 2007.
How do you ajust the door on a 379 pete
1987
Peterbilt 379
Dana-Spicer
No
where is the defrost actuators located
Stuck brake light switch, or a short to power somewhere in the brake light circuit.
There isn't a specific fuse for it... power is supplied to that circuit by existing fuses. You probably have a bad switch.