OK... so where do I begin the search?

The interior fan/heater/defrost/AC switch works. Plenty of air blowing through the vents.
However, I get no heat in the cabin. Fuses look good. Cooling system just flushed.

So taking on the simple places to look first, where do I begin?

Switches? Relays? or a heater core issue?

If you have air blowing either you heater coil is plugged or you temp damper is not moving between the heat and cool position and is staying on cool.
Are the hoses in the trunk area hot?

[This message has been edited by Dodgerunner (edited 10-15-2008).]

Thermostat not opening. Does the temp go up too high while running?

Has your heater core been bypassed. some people will do this instead of fixing a leaking heater core for a temporary fix. Open the front hood and see if they have looped the hoses.

I will check the hoses tonight.

The temp gauge is not working, and I most likely need to replace the thermostat anyway.

The car has been in storage for years.

I did pull a rats nest out of the blower/motor area.

Maybe it's time to take a look at the heater core.

If there is an air bubble in the system, you will not get coolant circulation, the engine will overheat, and the heater core will blow cold.

The most likely cause is either an air bubble or a plugged core.

Check the radiator as it warms up, if the radiator never changes temp, you dont have coolant flow. Chances are by the time you determine this, the engine is way over temp.

Take the thermostat out, top off the neck, then close the cap. Run the car for a minute, carefully crack the cap in the rear, then carefully remove the radiator cap in the front, coolant should come rushing out of it. If you dont have the rear cap at least a little open, there will be an airlock, and nothing will come out. Once it starts coming out close the front, top off the rear, leaving the thermostat out. Without the thermostat, the engine wont come up to operating tempature when driving, but it will help burp it and eliminate the thermostat as a possible problem for the time being.

Once you have everything figured out, make sure you put the thermostat back in.

At the very top of all of the forum pages is a link to Ogres Cave. Click on that and follow his directions in there to burp your cooling system.

Temp selector cable not moving? Or disconnected at either end? If the cable is set for cold air, you'll get air but no heat. Pull the HVAC unit out of the dash (takes about 2 minutes) and manually push/pull on the cable end. You should get some resistance but not a ton of resistance. If it won't move or if it moves very easily, make sure it's connected at the other end. If it is, you might have an issue with the heater core.

Check the hoses under the front hood which are connected to the heater core. They should be getting warm within a few minutes of starting the car.

Did you just aquire your Fiero? Make sure your thermostat is actually there! There are some uneducated folks that think it's good to run there Fiero in the summer without the thermostat to keep from over-heating....that's bad!
Marc

quote Originally posted by Patrick: Check the hoses under the front hood which are connected to the heater core. They should be getting warm within a few minutes of starting the car.

Checked the hoses, they are not getting hot. So what does this mean? Thanks!

quote Originally posted by VIPRE: Checked the hoses, they are not getting hot. So what does this mean? Thanks!

It means no flow. You have a blockage or air bubble somewhere.

I would start to make sure the hose are connected to the heater core, next, check the thermostat (if the temp gage and your not getting any heat - a missing thermostat will cause this - you have to go on a long drive to gain any temp), then last check the damper. You can see this on the passenger side (above where your left foot would be if you are sitting in the seat). Move the control on the panel and see if the end of the cable moves the lever (you may be able to hear the damper ope/close inside).

If that is all good, then I would suspect a plugged heater core - of course there is an off chance that the hose are blocked off at the engine as well.

Cheers

Awesome info.

Thanks a lot!!

quote Originally posted by LAMBO: It means no flow. You have a blockage or air bubble somewhere.

Ditto

Im still voting air bubble though, its the more common scenario.

[This message has been edited by 86GT3.4DOHC (edited 10-16-2008).]

You will find these under the intake on a 4 cly.


I will call these a pipe and a pipe adapter.
Water goes threw the head , heated, then is routed threw the intake to the adapter. Undertneath the TBI. Out the adapter threw the pipe to the 5/8 hose, then is piped to the heater core. Back into the engine threw the 3/4" hose in to the nipple on the waterpump. The adapter has a rubber orfice in it. Pretty small, around 17/64" Mine was plugged up. The big nut on the pipe is a one inch. After removing the pipe I just used a 17/64th drill bit with my fingers to remove the obstruction. It was just sludge-ie rust and junk. No problems since.
Good luck
Joe Crawford

[This message has been edited by josef644 (edited 10-16-2008).]

quote Originally posted by VIPRE: Checked the hoses, they are not getting hot. So what does this mean? Thanks!

As mentioned several times already, check to make sure you actually have a thermostat installed. This is a one minute procedure and an easy fix if required.

quote Originally posted by Mickey_Moose: I would start to make sure the hose are connected to the heater core, next, check the thermostat (if the temp gage and your not getting any heat - a missing thermostat will cause this - you have to go on a long drive to gain any temp), Cheers

Or if the stat is there and failed by sticking shut, I had that happen in a Grand Am before.