hello friends ,I have a 84 ,and im confused about the heater ,I can turn the heater on and sometimes I get heat ,and sometimes no heat at all,any suggestions on how to fix this? thanks Bill

 

Is your heater water control valve working? The valve is at the front of your air conditioning evap. housing, just behind the RH wheel housing.. With the engine running, move your temperature control slider on the heater control panel from COLD to half way toward HOT. The valve should be closed at COLD, then move to open at anything above the COLD position.

 

hot rod roy ,is this something that I can see without taking anything apart ,if I do need to take anything apart ,where do I start ,thank you for your time,Bill

 

You do need to open your hood!

 

yes I did that!!!!

 

yes I checked the the water control valve and it is working,what would be next?

 

You say that sometimes it works and other times it doesn't? Is the hot air in the dash and not being blown out or diverted properly? We need to find if it makes it into the heater core first.

If the under the hood valve works then is the hot water getting to the heater core in the dashboard? Usually you can feel the heat someplace under there if it is getting into the car.

These C4 Corvettes had as an option (Don't know about 1984) an Electronic Air Conditioning control system called a C68. Those use vacuum to control the little doors that divert the air. If you have a vacuum leak that would keep these parts from functioning properly. The overhaul of the C68 requires replacing you rebuild the air control box or whatever they call it.

While you are at make sure your car has plenty of coolant. Let us know more about your situation and we can all help you out. There is a lot of 1984 experience on the Corvette Forum!

Best regards,
Chris

 

fill radiator more

 

No Electronic A/C control on the '84. The sliding temperature **** controls a cable that is connected to a flap in the a/c duct (simple!). This cable is visible above the passengers foot well. Does the lever move when you move the temp control ****? (Key does not need to be on.)

You may have to remove a panel above the passenger foot area to see the lever. It's next to your ECM.

 

hot rod roy ,I will check tomorrow ,everyone thanks for the help so far!

 

Always start with the simple things. Make sure the radiator is full. If the coolant level is low enough it can do exactly what you describe.

 

Hot Rod Roy, Thanks again for teaching me about the 1984 Corvettes! Maybe now I understand why they are so popular!

I unfortunately have the complicated C68 and would much preferred a system with cables. I have always been a big believer of K.I.S.S. and love it when they don't try to impress you with technology not thought out well enough before production. The components of my C68 were designed for a 15 year life expectancy. The cable system was designed to last forever....Gee which would I want?

By the way the dash has the same 15 year life expectancy of the components used in it.

This is why I keep my 1968 C3, everything is "simple" and straight forward on that car. Even with transistorized ignition from the factory wasn't hard to work on. The only part I didn't like was the original AM/FM Radio. Mine was not working when I bought the car, after pulling it out and finding this giant transistor mounted on a big heat-sink I started to worry. I guess for October 1967 what should you expect? At least it "had" FM which made it tolerable. I love the simplicity of a car made to make power, the 427 has so much room around it it is amazing. I can change all eight plugs in 20 minutes from above.

I was intimidated by the complexity of the C4 at first but in truth it is a fairly simple system to get reliable fuel injection. Give me a FSM and my Snap On MT 2500 and I can do most of the maintenance for the C4 Corvette!

Best regards,
Chris

 

hot rod roy ,I will check that part on the passenger side this weekend,and let you know ,the radiator is full of antifreeze ,have a good weekend!! Bill

 

I did not see where anyone mentioned the heater core could be airlocked. Feeling the hoses won't always indicate if it's airlocked or not.
A quick test/fix is with the car up to operating temp, heater control on high, find a parking ramp or comparable with the steepest incline you can find and run the car up it with the tranny in low and the throttle as open as you can get. If it's airlock, with a touch of luck it will push the air through to the radiator.