Heater core replacement

The ENTIRE dash comes out. There are screws behind the speakers on each side and behind the defroster vent. Pls some on each end underneath and at the center where the console is.
You also need to drop the steering column.

Get a new core. They are not usually worth repairing.

does the hoses of the heater core get hot?
if they don't you need to flush it out or bleed the system better/more.

if they do then you can start looking into the controls.
vacuum operates all the doors of these trucks.

a common problem with these trucks is a bad vacuum line. they go into the cab near the brake booster.
rubber vacuum lines on these trucks seem to last about 4 years.

Here is a flow chart for troubleshooting. See if you can come up with any information that might help us get to the bottom of this.

Heater core removal from inside cockpit or through fender well???

from inside the cock pit. remove passenger side lower hush panel and glove box. remove cover to access heater core. **fairly easy job for the do it yourself mechanic.