no heat in the front of a dual system?

[OneofFew]

The rear heat works great, but only cold air coming out of front vents. Things to check? An actuator perhaps? It is a manual control system, not automatic.

 

[Big Mama]

Sounds like you’re on the right track check fuses and relays first

 

[Doubeleive]

you can pull the kick panel off under the glove box on the passenger side, from there you can see 2 of the 3 air door actuators it's usually one of those two that go bad, you can verify which one by watching if it moves or not when you switch the controls from hot/cold, up/down, etc.. whichever one doesn't move is the culprit. one of them may require a mirror to see if it moves or not because of where it is placed.
to iterate on that on the actuator has a round slotted hole near the center about the size of a pen that moves when the gear turns, you can see it move position by just looking at the slot position



I believe the 3rd actuator only controls defrost but I could be wrong it's not visible and is deep inside the dash, it is the least likely suspect.

 

[OneofFew]

I checked the actuator for the heat.... It works, sounds a bit elderly, but turns that slotted hole thing about 1/4 turn. I feel no heat in the A/c box, only luke warm air at best coming out of the vents. I am beginning to suspect a restricted heater core. Cabin air filter was super dirty, I think that is the heater core behind it? It was luke warm at best. I did not see any significant dirt build up on it. A/c works fine.

 

[Doubeleive]

the vehicle temp goes up to normal? does the temp gauge move around a lot or does it stay pretty solid in one spot?

 

[OneofFew]

the vehicle temp goes up to normal? does the temp gauge move around a lot or does it stay pretty solid in one spot?

Oh yeah, coolant temp is good, steady and verified with a scan tool, just got done doing a radiator, Thermostat and fan clutch. Rear heat works well.

 

[Scottydoggs]

get up to running temp, then pop the hood and touch both heater hoses to the firewall. if one is cold or both are only warm the core might have air trapped, or its clogged up.

pop the hoses off and use a garden hose to flush the core out.

 

[Erickk120]

I have something similar, for me, everything gets heat except the driver side. So everyone is roasty while I have to shake, good thing I live in Florida otherwise I would look into it.