Without knowing the make and model this is difficult to say
The 1999 Acura air-conditioner relay switch can be found in the fuse box. The air conditioner relay switch will be in the third column, second from the top.
.....still lookin'
The 1992 Chevrolet Suburban air conditioner compressor relay switch can be found in the fuse box. The air conditioning compressor relay switch will be labeled as such.
The 2000 Chevrolet S 10 pickup truck air conditioning relay switch can be found in the fuse box. The relay switch will be in the third column.
The air conditioning compressor clutch relay is located on the bottom of the air conditioner compressor. The relay switch will be labeled.
You should be able to switch the relay with the horn relay and then check to see if the horn works.
My guess is the system is low on freon being 11 years old.
which is the air conditioner relay on a 99 ford ranger
The 1991 Ford Explorer air conditioning relay switch can be found on the firewall in the engine compartment. The air conditioning relay switch will be on the drivers side of the firewall.
You can find the air conditioner fuse for your 1990 Ford in the fuse box. The fuse box is located beneath the drivers side dashboard. The fuse box will also contain an air conditioner relay switch.
switch, relay or blower motor problem as a guess.
thermostat could be bad, or location of it, air flow over it.