96 Grand AM no AC or Heat

[conflikt]

Hi I'm new to the forums and have a question... For some reason I have no heat or AC and ac was recharged when the heat does work it comes out with very little heat. A few days ago I changed the thermostat thinking that may be the problem and bled the new thermostat with no luck. So now I'm thinking It's the heater core. The problem is I dont smell antifreeze and can't tell if its leaking because my windshield leaks a little and causes water on the floor of my car which i tried to fix today. I bought the new heatercore today and got most of the work done dash removed and consol removed for easy access to the heater core took out all the screws to the heater core casing but cant get the casing to come free? Can someone give me some help of why I might not be getting heat and why the casing wont come off if i took out the screws.

[skibum1111]

The casing around the heater core won't come off because there is one screw way up in the front of the heater box. If you crawl around under the dash and look towards the center of the heater box on the bottom almost to the firewall there is one screw. I got mine out by breaking the bottom of the box (not recommended as they tend to leak after that), and discovered that I could have gotten it out by using a bit for my drill and a pair of pliers. Once that screw is out the bottom part of the heater box comes right out and the heater core should pull out. Good luck, its very cramped under the dash.

[conflikt]

OH OK do you think that from the water leaking from the window on the floor that the moisture may have rusted the heater core causing it to malfunction? Also yea it's tight under there I'd say good luck getting to it without taking off the dash because removing the dash made it so much more easy to do and I'm a small guy. The reason I think it's the heater core is because I'm not getting heat or AC but the blower is working fine. Also I guess a mechanic said to my girl friend that the Intake gasket had a slight leak. But I don't think that it's leaking I guess I'll spray some WD 40 on it and see if I see bubbles. And if so I'll replace it but it cost 85-95 at Auto zone. I hope this works and if not what could be the reason I wouldn't be getting heat or ac? Also I'll make sure I look for that screw I didn't see it but it started getting dark today so maybe I missed it

[xeroinfinity]

Your heatercore is brass, they dont rust.

First I would ahve disconnected the heater hoses and used compressed air or a garden hose and see it the heatercore is frree and not pluged causing the no heat.

Though, your mechanism that controls the heat ot ac could be broken not adjusting the temp properly.

So you removed the whole dash for the heatercore?
That was not really nessesary, just more work.

[crazy Jim]

I would have checked the vents first to insure they were operating correctly as well as the coolant level before I went to the trouble of removing the heater core. My '99 caddilac had a vent issue that was resolved by clearing the ECM by removing positive lead from the battery and touching it to the negative side. In my '99 Grand Am the heater would take 10-15 minutes to begin to blow warm air when the coolant level was low (leaky manifold gasket). Now it gets warm within five minutes.

[conflikt]

Xeroinfinity, I should have done that, but I didn't maybe the heater core is clogged but I don't believe so. My fluid doesn't have any residue in it and my girlfriend said this has been doing this for a few years. The reason I think it's the heater core is because no heat or ac. But the blower is working fine and I replaced the thermostat and bled it with no luck. Also the old motor was replaced in this car because my girlfriend blew the other one up the dealership replaced it with another motor. So this one has about 65k on it I also know that the heat did work before same with the AC. Well I guess I'll find out today if its the heater core or not if not isn't there a damper door switch that could be bad? Jim the coolant level is fine that's the first thing I checked and the vents are fine I just don't understand how it sometimes blows a little bit of hot air but its still cold and at other times it blows nothing at all.

[conflikt]

OK new heater core installed. Man was it a pain getting those lines connected back on . OK still no heat and the top vents are not working now? I also noticed when I change the air from hot-cold that the line pops off? Could the line popping off be the problem and why would the top vents not be working now? I also can hear the fluid going in the new heater core so I know its working.