Where is air condition relay on 1990 Nissan D21 truck?

On a 1990 Nissan D21 truck, the air conditioning relay is typically located in the engine compartment, near the fuse box. It can often be found mounted on the firewall or near the battery. You may also refer to the vehicle's service manual for a specific diagram and location details. If you're having trouble locating it, checking the relay itself for a label can also help.