I have a 1990 Camaro RS 305 TBI, for some reason the vents aren't blowing, neither hot or cold air, nothing. Can someone give me some suggestions on how to trouble shoot this or fix it. Thanks Have a good day

 

take you top dash board off,mabey all the hook ups are not in place,i had my dash apart one time and then mine did that too,i forgot to put them back in place

 

There are two main possibilities here, but I will need more information. First, is the fan actually turning on? If yes, then check the defrost vents (up by the windshield). If the air is blowing from them, then chances are you have a vacuum leak in your vent system. The most common thing is for the vacuum hose for this system (the small hard hose that leads from your intake into the firewall) is damaged or unplugged.

If the fan is not coming on at all, then you probably have an electrical issue. The most likely causes for this are the A/C fan switch, relay, or blower motor. To test these, first have the ignition on, but with the engine not running. Then switch the A/C system from "off" to "max" or anything else thats not "off". Then turn it back off. If you hear a click each time, then your relay is good. In this case turn it to "on" and tap the blower motor (on the passenger side, on the firewall) with a hammer. Don't bash the hell out of it. If it kicks on a little, then its probably your blower.

If the relay never kicked over, then suspect it or the fan switch. Both are pretty cheap, so you may just want to replace them both if you suspect them at all, instead of spending a lot of time testing.

Sorry for it being so long. Pretty much an all purpose diagnosis of the fan/vent system.