Air Conditioning Help
Thread Starter
Heel & Toe
Joined: Jul 2024
Posts: 20
Likes: 2
Air Conditioning Help
Hi All!
Need some help with my 79, i currently have no heat or ac. The guy i bought it from a few weeks ago said he believes his father removed the heater core because of a leak. (someone told me they think it was not removed just bypassed). However he said it also doesnt have A/C because it is all the same system. Is this true? I have nothing coming through my vents either, i believe my blower motor is bad because it makes an awful groan/rumble when the battery is on..
Let me know!
thanks!
Need some help with my 79, i currently have no heat or ac. The guy i bought it from a few weeks ago said he believes his father removed the heater core because of a leak. (someone told me they think it was not removed just bypassed). However he said it also doesnt have A/C because it is all the same system. Is this true? I have nothing coming through my vents either, i believe my blower motor is bad because it makes an awful groan/rumble when the battery is on..
Let me know!
thanks!
Le Mans Master
Joined: Jun 2019
Posts: 7,655
Likes: 2,469
From: Indiana
Suggest posting many pictures of engine compartment , firewall, hvac controls in the interior.
the fan will run at all times so it may be bad and or packed with debris.
here is my fan thread
https://www.corvetteforum.com/forums...d-working.html
the fan will run at all times so it may be bad and or packed with debris.
here is my fan thread
https://www.corvetteforum.com/forums...d-working.html
Safety Car
Joined: Dec 2012
Posts: 3,815
Likes: 1,726
From: Summerville SC
The heater core and the A/C evap core are all in the same HEATER box on the firewall. They control the air temps by opening and closing valves letting more hot water or more freon thru the system. The blower motor could be bad but also could just have lots of crud ( leaves and things) in the housing which is making the noise when it turns on. This is not a simple easy fix. If you are going to replace the evap core you need to open up that box on the firewall and there are a lot of vacuum operated controls/valves inside the car also. If you are mechanically inclined it is doable with the proper shop manuals, etc. If not, it would be best to take it to someone who knows about these old cars. Post some pics and we might be able to help get you started. 
Safety Car
Joined: May 2001
Posts: 4,757
Likes: 1,647
From: Fairfax Virginia
Have you tried to measure the current being drawn by the blower Motor? I would do that before going to much further. Using a "Power Probe" I would consider putting 12 volts directly into the motor and see if there is any difference in operation or sound. Verify that the blower motor is grounded properly as well. On my C3 when the blower failed to work was frequently caused by the ground wire slipping off the terminal and nothing more. Now it has a tie wrap holding the ground wire in place so I don't have to deal with it again.
interpon mentions checking the fan for any debris that could have worked it's way down there. This is a great idea as I have found old Holly bush leaves and other junk inside the blower fan.
Replacing the heater core is up to you, I would fix it myself but it is easier to get to the parts on my non a/c 1968 C3. My blower motor is mounted on the firewall and can be removed very easily unlike many of the newer Corvettes. With my 427 I have been very glad to have a working heater core that allows me to dump extra heat when needed.
interpon mentions checking the fan for any debris that could have worked it's way down there. This is a great idea as I have found old Holly bush leaves and other junk inside the blower fan.
Replacing the heater core is up to you, I would fix it myself but it is easier to get to the parts on my non a/c 1968 C3. My blower motor is mounted on the firewall and can be removed very easily unlike many of the newer Corvettes. With my 427 I have been very glad to have a working heater core that allows me to dump extra heat when needed.
