Where is the high-low blower relay for heater on a 1992 Chevy lumina APV?

The 1992 Chevy Lumina APV doesn't have a single "high-low blower relay" in the traditional sense like some cars. The blower motor speed is controlled by a resistor pack and the blower motor itself, with the control coming from the switch on the dash. There might be a relay associated with the blower motor circuit, but it's not directly a "high-low" relay. It's more likely a relay that provides power to the entire blower motor circuit, regardless of speed.

To find the relevant component(s):

1. Check the Blower Motor Resistor: This is the most likely culprit for blower speed issues. It's usually located behind the glove box or under the dash, somewhere near the blower motor itself. It's a small box with several wires connected to it. Inspect this for damage or burnt resistors.

2. Look for a Blower Motor Relay: This relay might be in the under-hood fuse box, or possibly in a secondary fuse/relay center inside the passenger compartment (often under the dash). Consult your owner's manual or a wiring diagram for the precise location. The relay itself might not be specifically labeled "high-low," but it might be related to the HVAC system or blower motor.

3. Wiring Diagram: A wiring diagram for your specific year and model Lumina APV is essential. This will show you the path of the electrical circuit and where the relay (if one exists for the blower motor) and resistor are located. You can find wiring diagrams online (often on forums dedicated to classic Chevy vehicles) or at auto parts stores.

Without a wiring diagram, pinpointing the exact location of a relay is difficult. Focus your search on the areas mentioned above – the resistor is crucial, and a relay might be nearby in a fuse box.