Well,
In Texas it does get a little cold in the mornings... unfortunatly the heater in my Formula does not blow hot air, it stays nice and cold.

Where should I start to figure out what is wrong?
I know nothing about the AC-systems on these cars... (or any car for that matter).

Help me out!

Thanks.

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http://kiztope.50megs.com
92 Pontiac Firebird Formula WS6 5.7/A4
K&N, Blue Streak Cap and Rotor, strange unknown exhaust system (sounds good though)...
Mods are in direct proportion to income!

92 Rs 3.1/T-5
Beautiful car, many mods, but now I am turning attention to the 'bird!

AIM : Theonekiztope
ICQ: 8787542

"Maybe one day life will take a turn. When it does Lean into it!" Leon Calrinsky (98)

 

It could be a number of things. First listen to the vent when you swich over from cool to heat. It should make a mellow clunking sound. This indicates the vacume lines are intact and closing the vents. If you do not hear that sound then most likely a vac line behind the heater controll got disconected. It can happen when you replace a radio.
The other thing it would be if the vac lines check out ok is the heater core. The heater core is the culpret 90% of the time and is a really fun job especially when you have ac. You could disconect the heater core lines in the engine compartment hook a hose upto the top one and run water through it to unplug it. It might be a good idea to flush your cooling system to make sure everything is nice and clean.
Good luck!
SSC

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85 Camaro Z28, Cowl induction hood, Black-355/TB400,3:42 posi, Tons of goodies but if you ask, "Its stock"
82 Firebird, White, red in six months-355/TB350,3:42 Powertrax posi. Not an insane amount of goodies but it runs like a motha!
76 Chevy C10, Firemist blue, 355/Muncie HD 3speed,3:73 TorqLine posi. Show me another 12sec@4800ft SBC street truck??
91 GMC 1500 Sierra 4x4, Red, Was 4.3 now the proud recipient of the Firebirds LG4. 305/5 speed.
56 Buick Special, OG Blue&White, V8/auto. Maybee one day I'll get it going.

 

I would replace the thermostat. If yours is still original then the chances are it is not closing all the way thus not allowing the collant to reach its hot temp.

Good luck!



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89Iroc, 305 TPI, WC T5, 3.08 Posi, Flowtech Headers, 3 inch over the axle, Flowmaster 80, Aluminium Driveshaft, Ported Plenum, Air Foil, K&N, AFPR, Smog/AC/Cat Delete, 3300lbs, All free mods

 

SSC:
About the Vaccum lines... It does make the releaseing noise when I switch it over from cool to heat...

So you think it could be plugged up or something?
I live in an apartment complex so finding a hose is a problem.....
I gotta do something though, It is just getting colder now! Good ole, cold front....

DANIELEK:
Even when the car is almost to 220, the heater is not hot.


Any other ideas?

------------------
http://kiztope.50megs.com
92 Pontiac Firebird Formula WS6 5.7/A4
K&N, Blue Streak Cap and Rotor, strange unknown exhaust system (sounds good though)...
Mods are in direct proportion to income!

92 Rs 3.1/T-5
Beautiful car, many mods, but now I am turning attention to the 'bird!

AIM : Theonekiztope
ICQ: 8787542

"Maybe one day life will take a turn. When it does Lean into it!" Leon Calrinsky (98)

 

I just went through the same situation (search this board for: "Replaced the heater core for NOTHING!" if you're curious), so I feel your pain, even if you're in warm Texas.

(1) I assume you're not getting any coolant leaking down the passenger floor. This means that either (a) your heater core is clogged so no flow, or (b) your core is fine.

(2) Simple (2 minutes, no tools) check for vacuum pressure to heater valve:
Our cars (my 91 Formula) have pretty much the same setup: instead of coolant running through the heater core all the time, like on older 3rdgens, we have a Heater Control Valve (HCV), sitting clearly atop your psgr. valve cover, which only allows flow through the core when you have heat switched on from the AC controls inside. The HCV has 3 hoses and one obvious little vacuum line going to it. With your engine on and HEATER OFF inside, pop off the vacuum line and you should feel a little vacuum. Now, turn HEATER ON, and the vacuum should go away.

[[NB - if you don't have any vacuum at all, a functioning HCV should allow flow through the heater core, so I don't know that this matters]]

(3) If you feel the vacuum change (hopefully), that's all working fine. Next thing to think about is the HCV and flow through its hoses('cause you want to rule everything out so you don't unnecessarily replace the core like I did!!). The HCV hose at a 90* angle to the other 2 brings in warm coolant from the engine. The other 2 are: (1) bypass hose that T-connects into the hose coming from the core to the radiator, right by the radiator cap and the overflow tank hose and (2) hose to the heater core.

Hose (1) should always have hot flow when the engine's warm enough - >195* - that the thermostat is open AND the heat is off (ergo, normal vacuum to valve). Is this hose hot and pressurized? With the engine cold, take the radiator cap off, and spray/pour some water into this hose -- you should see evidence of the flow entering the radiator right there. If not, it's blocked somewhere and that's your problem.

Do the same thing with hose (2) (the hose to the heater core) if you don't see water coming into the radiator, the core is clogged. You can try to clear the clog out (I think somebody makes a liquid for this purpose, or u could just put a lot of pressure into it with a hose...?), but you're taking your chances that you'll make the thing leak onto the passenger floor in your car... I had this happen to me a couple months after unclogging a core on my old car (it's messy).

Don't replace the core unless you have to, but if you do, it's not that bad, just takes time and patience. If you need more help or if I accidentally gave bad advice, post again...

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Joel Geerling
Red 91 Formula, 305 TBI
Edelbrock 14x3 open element
TBI 1/2" spacer
Hypertech street chip
Crank/Alt Pulleys
180* stat
*
Exhaust is next!

 

Damn, I wrote a friggin' book. I need to start goin to bed earlier... less caffeine...

 

I don't think the heater switch is operated by a vacuum switch. That particular switch just directs where the air flows out from (vents, defrost, etc).

At least on my car the climate switch (red to blue) is completely manual.

If you remove the panel under the passenger side dash (where the ECM is) you should see a plastic enclosure. Inside this enclosure is the heater core. As you move the climate switch from blue to red you should see the enclosure open. All this does is introduce hot air from the heater core to air coming in from the blower motor.

If the door doesn't move or is stuck closed, then there is your problem.

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ORIGINAL OWNER
92 Camaro RS, LO3, 5-spd, T-tops

Performance:
K&N Open Air Filter, Partial TBI mods, Edelbrock performer TBI intake, Fastchip Prom, Timing +4 degrees, Centerforce clutch, Xact 8mm wires, SLP 1 3/4" Headers (coated), Flowmaster Catback Exhaust, Richmond 3:42 gears, Torsen HD Posi
Sights & Sounds:
Alpine 8030 Alarm System, Valentine One Radar Detector (How did I ever drive without one?), Pioneer DEH 7450 Head Unit w/6-pack CD changer, Pioneer DEQ 7600 Sound Processor, 2 Kenwood KAC-846 Amps powering 2 12" Pro Red subs, 2 Pioneer 6x9 and 2 MTX 4x6 speakers. Spectre valve covers and accessories, Z28 grille w/aftermarket lights, MacEwen whiteface gauges
NEXT UP: the rest of the TBI mods & Suspension upgrades

 

Pukka,

You're right that the lower lever (blue <-> red) manually operates the door in the heater core's plastic housing, but the upper switch (Off/AC/heat/vents/defrost...) does change vacuum to the HCV - if yours works, you can easily verify this by the method I listed above.

JG