Heat and Defroster not working on 85

[avp0713]

Hello all

No heat blowing from the vents. Installed new blower motor, had mechanic check grounds, still no blow!

I don't have the time to try and fix this myself and its too cold out anyway for driveway attempts.

What should I expect if I give the car to a qualified mechanic and say "I need to have the HVAC system working?" Should they be able to deliver the car back to me fully operable? Or is it advised to bring him all the parts that it may need?

Its my old vette that I have given to my HS senior son.

Thanks
Tony

 

[avp0713]

No blow or no heat ; two separate problems.

Man or Elec HVAC?

This is the manual HVAC panel.

From what I remember, even if the blower is not working, one would still feel slight heat coming from the vents; I feel only the slightest sensation of warmth emanating from the vents, the slightest.

As mentioned there is a new blower installed. Is it possible that the heater box in the engine compartment has a hole melted in it (from the headers) and the heat is escaping that way? That is just something that I surmised might be the problem. IDK, I have no idea really.

Any suggestions?

Thanks

 

[avp0713]

But you have not yet confirmed if the new blower is working!
Can you blow cold air at full force????

No, no air is blowing out of the vents regardless what setting I choose. I do hear a noise that sounds like vacuum suction???


NO
because the heater core that the heat comes from is inside the car
If core is blocked you will get no heat.If hoses to it are blocked ; the same.
Also a vac operated shut off valve on heater line may be faultly stopping hot water reaching core.
Many possibilties

Start by confirming you have airflow.
Possible for ducting to get blocked with rubbish restricting airflow to system

No airflow into car. At one point before purchasing a new blower motor (last week), it was operating - sporadically - hot air was blowing through the vents, but moving the slider to another setting would make it stop blowing.... perhaps an electrical issue?

 

[avp0713]

So the problem at this point is no airflow ; not no heat?


Possibly the blower switch in control panel is faulty
Can you make the blower work by putting 12V direct to the motor? (there is a plug on the wires close to motor you can disconnect to to this )
Confirms motor is good

I will confirm over this weekend that the motor is good/working. Will also check if the control panel is faulty. Will report my findings Saturday evening. Thanks for your help with this.

Tony

 

[avp0713]

Ok, Brought the 85 Vette into the shop on Saturday, tell the tech "There's no air blowing out the vents" and "another shop installed a brand new blower motor". He says bring the car in on Tuesday.

Tuesday afternoon he calls and says "I see rust in your radiator, you should bring the car to Jims Radiator shop across town.".. I say "rust in the radiator? It's only 3 years old" and "did you feel any air blowing out the vents? Did you turn it on high/low, cool, vent?" He says "no I didn't, Ill check that out".

Fellas, this is a shop with a very good reputation, all the local car enthusiasts in Ocean County NJ talk about this guy (Meineke Mufflers, Brick, NJ). Why is this kid calling me without turning on the system? How do you suggest to someone to bring your car to the radiator shop if you haven't turned on the system yet????"

3 hours later, he calls me back and says "OKAY! Your Blower Motor Resistor is bad its a $35 part, we'll order that for you, and you had a bad ground; we ran a new ground" Your car should be ready Wednesday afternoon; Price? $220. ($100 diagnosis, $70 labor, $40 parts).

I'm still a little pissed but I'm happy that he's got a hold of the issue.

I have my teenage son pick up the car and he tells me it's blowing nicely. When I get home several hours later (1am) I take the car out on the highway for a test ride; Yeah, its blowing now, but it's blowing cold air.

I'll have to take it back and tell him, it's not blowing hot air. I'm guessing perhaps its the blend door? IDK.

I honestly don't think rust in the radiator would stop it from blowing hot air?

Any suggestions?

Thanks
Tony