My heater/ac only works on level 5 and not 1-4 wat could be the problem?

Cabin air filter? Blower motor working on all speeds? Critters building nest in heater box

sounds like you need a new blower resistor, its under the dash on pass. side. if it goes bad your blower will only work on high. its fairly easy to change

ok that means that speed number 5 on the fan blower is bad or your climate control unit is malfuntioning

or you trying to use the A/C if you are then have the compressor checked and the freon level checked also last summer had the same problem with my truck gave it a quick charge and it worked just fine so they maybe the problem

Here's a list of possible culprits:

Priority Action Part Type Cause
1 Inspect - Antifreeze Needed - Coolant Level Low.
2 Inspect - Heater Control Valve - Leaking or Faulty Heater Control Valve.
3 Inspect - Thermostat - Thermostat Stuck Open.

First thing to check is your engine coolant level - quick and free.
Since your blower works, my nominee for the offending part would be the Heater Control Valve, which redirects hot coolant into the passenger compartment heater core. Without hot coolant, the blower will just blow cold air, since the heater core isn't getting the needed flow of hot coolant through it.
There may also be a fault in the "Temperature Valve Actuators" (there is a right hand and a left hand version of these - one for each side of the car).
The Right hand Temperature Valve Actuator is AC Delco part #15-72971.
The Left hand Temperature Valve Actuator is AC Delco part #15-72972.
Their pictures are available in the online AC Delco Parts Catalog at:
http://parts-catalog.acdelco.com/catalog/catalog_search.php
Here are your parts search parameters:
Vehicle: 1996 OLDSMOBILE AURORA V8-244ci 4.0L F/I Vin C ID# 17739
Group / Subgroup: Heating/AC / Heater Core and Htr Control Vlv

sounds like compressor isn't working properly or heater vacuum is opening vent to heater core.try turning on ac and if it cuts on and off repeatedly every few seconds the freon level is not correct or high pressure switch may not be working make sure radiator fan comes on when ac is on.if all this is working properly check vacuum hoses to heater may be opening vent doors to heater.hope this helps

That is the way the festiva is designed. Heat only works on the defrost and the floor. Fresh and AC (if equipped) come through the vents.

it is must likely your fan control model -it control's
the fan speed location of model is next to blower

evaporator board needs replacing located inside blower area under dash

you need to replace the resistor block or clean the contacts on the heater fan resistor block plug. find your fan and follow the wire to find the resistor block. it will have 5 wires coming out of it and be mounted in the duct work for the heated/ac. remove a few screws and pull it out and put the new one in. Mike