Thread: No heat

I just added another GP to the fleet a few weeks ago and have a question about not getting any heat into the cabin. It's a 97 GT with 70k miles. I didn't have a chance to dig deep into it yet but I wanted to see where I should start looking. I checked the heater hoses into and out of the firewall. They are both hot leading me to believe the t-stat and heater core are ok. I'm leaning toward the heat control dial. Is there something I can do to test the heat control to see if it is working? If it isn't the heat control, what else should I check?

Another small annoyance is the fuel gauge will only work until it gets to around 1/2 tank. It isn't an issue since I'll just watch the miles between fill ups so I'm not too concerned. What is typically the cause of the gauge to not work properly?

Overall for the age of this car it drives better than my '05 with 53k miles.

What climate control do you have? I would check to see if the blend doors are moving. That's most likely how to tell what is causing the lack of heat. Although the root cause (if you observe this symptom) is likely the control module. Before replacing, try pulling the hvac fuse and re - inserting, then turn key to accessory and allow doors to calibrate. If they still do not move, it's your control module.

Things are a bit different with the auto hvac, as it could also be a vacuum issue or vacuum control issue.

Thanks for the reply. It does not have the auto hvac. Just the simple turn the dial to the desired temp. Should I be able to hear the blend doors moving or is it a visual thing? The vent selector switch works ok as far as defrost and floor positions.

If it's the dual climate, then you'll have one on each side of the center console up under the dash. You'll Have to remove the foot panels to see them. They should make a sound, but it might be hard to hear and easily mistaken for other sounds. Their only function is to move the door between the heater core chamber and the evaporator core chamber (hot and cold).

If it's dual, most notice one side is hot and other is cold etc.

If doors don't move, you could check for current to actuators to make 100% sure before condeming them or the head unit.

Let me know what you observe and I can talk you through more troubleshooting.

Also, this goes without saying, check your hvac fuses. (Although probably not an issue)

I believe it has something to do with the actuator. It started working yesterday and again this morning it was ok. I could hear it moving and it sounded like it was struggling. Do you think it's the actuator going bad or the blend door is hard to turn?

Usually it's the blend door actuator not the door, but just as scotty said, try taking it off and moving door by hand