01 LW300 heater

Now that the weather has turned warm, I am noticing that even with the
heater control full counterclockwise, the air temperature from the duct is
still hotter than the outside air.

Any ideas on why this is? Not sure if it is in the internals or just air
heated by going over the hot hood and into the intake. I'm pretty sure that
the gasket between the firewall and hood is tight so no hot engine
compartment air is getting sucked into the duct.

Oppie