The heater is not blowing hot air in the CAB?

Hi,

There is one. It's in the engine compartment, RH rear side of the Inner Fender. Keep in mind, it is actuated by the engine vacuum, so make sure the vacuum hose isn't disconnected and is providing an engine vacuum when it is running.

Let me know if you find it.

Joe

See pics below.

Hi,

The heater control valve should be connected to the heater core hoses right before the firewall where the hoses attach to the heater core. If you look at the pic below, the arrow is pointing towards the front of the vehicle. The pic is at the firewall.

Let me know if that helps. Also, if you could take a couple of pictures of what you are seeing and upload them for me to see, it may help. Let me know if the truck has factory AC as well. I don't think it makes a difference, but anything is possible.

Take care,

Joe

See pic below.

Hi,

If there was no valve, you would have heat at all times. The valve is to stop the flow of coolant to the heater core.

Do me a favor. Check for the production date of the truck. You should be able to find it on a label under the hood or on the door frame. I have a feeling this truck is a late-year production vehicle. If that is the case, you will have an electric blend door actuator under the dash. See pic below. That was the design used on the 1997 trucks. If it was made late in the year, they may have used that design. It's a theory. Let me know.

Also, I want you to check something for me. Turn the heater on high, start the engine, and allow the engine to reach operating temp. Once that is reached, turn the engine off and feel both heater core hoses. Both should be hot; one will be a little hotter than the other. Let me know what you find.

Joe

See pic below.

Hi,

No problem whatsoever. I was going a bit crazy before Christmas as well. I'm still going crazy. LOL

As far as the actuator, see if moves when you change the temp request.

Let me know. I hope you had a nice Christmas as well.

Joe

Hi,

The actuator is approximately centered under the dash. If you look at picture one below, I highlighted the actuator.

The remaining two pics are the removal, adjustment, and installation procedures. Note that the adjustment procedures are done with a new actuator connected to the electrical system but not installed.

Let me know if this helps.

Take care,

Joe

See pics below.

Hi,

There may not be anything blocking it. If there is, it will be an insulator panel that will either be screwed in place or clipped. Working under the dash can be a pain. There simply isn't a lot of room.

Let me know.

Joe