It clicks on and off every 20 seconds and doesnt cool

Hi Donna,
Check outdoor unit is running - the larger pipe/fitting of the two should be cool to touch after about 20 minutes, and the small one should be hot - if not either the system is short of refrigerant or the compressor is not running.
Check to make sure the settings are correct - snowflake for cooling - not for wintertime
Good luck

Sounds like the compressor is frozen - sound you hear is the clixon a special sort of resettable fuse on compressors. When they do not start or overheat, it kills the power - when it cools power is restored until it reheats again and .......................

Use ammeter to confirm this - it will show a much greater than normal current draw.

Without a compressor analizer you will need to check the winding
resistance. or you can just cross your fingers and hope the relay
and start capacitor are the problem. Sounds like the condenser coil was plugged so you could possibly have a locked up compresor.I doubt it is low on refrigerant charge.

Feel the compressor top Kim. I need to know if it is too hot to keep your hand there. If yes it is too hot then unplug untill someone can perform the test listed below. If there frigerator compresasor pass that test it will be safe to replace the start relay=> RF-4800-48 Start Relay or here=> RF-4800-48 There are no photos of the overload start relay and the part installs under the cover on the side of the compressor.
Unplug the refrigerator and remove the back panel that covers the compressor. There should be 3 wires going inside the cover of the compressor. Mark all 3 and mark their location so if compressor is OK you can put them back in same order. The plastic cover may snap on and you may need to squeeze the sides to unlock the cover and sometimes there is a metal clip holding the cover in place. Remove the cover. May look hard but it's simple. There will be three connections under the cover and 2 will go through the start relay. Unplug them leaving the three prongs exposed. They may be marked R =Run, S=Start and C=Common. Set your meter on continuity and then begin by testing 2 at a time until you have checked S to R and R to C an C to S and S to R again. You should get a reading all the way around. If no reading between any of the pairs as you go around you should get no reading between any two the compressor has an open winding and is defective. Then if it passes that test then touch one probe to R and the other to the copper pipes or clean metal on outside of compressor, then S to metal outside and C to metal outside. If you get a reading this way even just a little. The compressor is a burnout. Then let me know what you find. Thanks, Sea Breeze

Clean the flame sensor not the igniter . check air filter is clean .

20 Years is a long time and we need to suspect quite a number of components. It is possible that the compressor is quiting as it overloads and then restarts when as the temperature is not maintained. Please check the capacitor to the motor, check the relay . Also if the pressure switch is faulty it can cut off. So a full check up starting with the compressor , the gas pressure and the electrical switching relay must be confirmed.

You likely have a restriction in the heater coolant hose circuit - perhaps a coolant control valve not fully opening, or a kinked hose.
Insufficient coolant volume is flowing to keep the heater core hot.
Try back flushing the heater core system with a garden hose to check flow.

The overload/relay which pluggs onto the side of the compressor is bad . Pt # 2262181

it depends on how severe the power spike on the outage was,if your lucky it may just be the contactor,if not comp time,you can open the contactor case and manually start the compressor,use an insulated non-metallic device to do so

Try first replacing the relay(located on the side of the compresor)wich the part won't cost more than $20.If doesn't work the compresor is stuck or burned and you need to replace it.