Where is the heater blower relay located on a 1999 Nissan Frontier?

The heater blower relay is under the dashboard on the passenger side of the compartment. It can be located by looking up underneath the glove compartment, and attaches itself to the ductwork. It is held in by 2 small screws and has wires attached and visible. The relay is easily replaced.

That is where the resistor is...

The relay is to the right of the fuse box on the driver side near the parking brake. there are a row of relays and they are (from top to bottom): tail lamp relay, ignition relay, accessory relay, rear window defogger relay, and the bottom one is your blower motor relay. The resistor is in the ductwork on the passenger side. both cost around $20 and I have been able to find a motor for around $30. All are easily accessible and easy to replace