I've had the truck going on 5 yrs. Never had great heat, but it's getting
worse. Now it practically has no heat. What little there is comes when it is
idling. Start down the road and it's cold air.
SYMPTOMS: No heat (very, very little anyway) when moving. SOME when
WHAT I'VE DONE: (in the last 6 months)
+ New Radiator
+ New water pump
+ New thermostat
+ New heater core
Both heater hoses are hot once the truck is warmed up.
A bit warmer air when you turn it to "recirculate".
I'm wondering if it's a vacumm leak somewhere. Is the heater control/blend
door vacuum operated?
Truck has 290,000 miles. Never been to a dealer since I've owned it but I'm
throwing in the towel. Have an appt next Tuesday but if ya'll could help me
before then I'd appreciate it!
Most likely the door controls. They are vacume operated, but there's a
mechanicla linkage to actually move the doors. If the core was replaced, I'm
surpised nobody inspected the box to make sure everything was working correctly.
The mode door is vacuum-operated (selects defrost/panel/floor vents). The
blend door is mechanical. It's spring-loaded, and a steel cable connects to
the dial on the HVAC controls.
Remove the dash bezel (two screws in the cupholder, two in the ashtray),
then remove the HVAC control (3 or 4 bolts/screws). Disconnect the cable
from the control on the back, and tug on it gently. You should feel some
tension on it. If it goes slack, the blend door is probably wedged. To
repair that means removing the HVAC box, and that means recovering the A/C,
draining the coolant, and removing the entire dash. Not a very fun job...
Excellent reply. Sounds like I'll be going back in. I've exhausted all
other options. I've never had the truck to a dealer - always done all
repairs myself. But this one has me stumped. My wife says "take it to the
Then I told her of a couple of stories on the 'net similar to mine where the
dealer charged $1,000. She changed her tune and wants me to give it one
more try ;-)
Thanks for the advice. Sounds like I'm going to take the dash/HVAC out.
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