Help me wrap my head around this. I "think" that when I pull the heater lever it grounds the relay and sends 12v to the blower motor. Is that correct? Also, what powers the small bulb on the Blower indicator next to the lever? I only have one black wire connecting it and from what I can tell from the flow chart it appears to be positive coming from fuse 9. Is that correct because it's not getting 12v with the key on. I do see a small screw - see pic's - should it receive some connection. If so, where does the bulb get its ground? Also, the wires connecting the blower are faded so I'm not sure which is which. I'm not getting power to either one presently so the volt meter isn't helping any. If it's reversed won't the motor simply run backwards since it DC? TIA, Kent

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The bulb lights with either parking or headlights, thus ignition switch my be off.

But what about a second wire for the lamp? Is there one; where would it connect; + or -?

There is a brown wire with an eye terminal that should be under the left side nut securing the light fixture. It's part of the gauge cluster harness and should be under the carpet.

Looks to me that the brown ground wire is in the wire nut that is supplying 12v dimmed power (bk/bl wire)

The brown ground wire is shared with the center console gauge grounds. If I’m seeing it correctly in picture the brown wire coming out of the lamp is just a stub soldered to the terminal. Probably going to have to remove and extend it to make use of it and to get it connected to proper ground shared with gauges (located under carpet as mention by prior post).

You could tap into a ground wire at back of gauges without having to lift carpet to get it to your indicator lamp if original ground can’t be located.

Lose the wire nut. Crimp properly / use insulated connectors if you want to keep easy disconnect capability. Wire nuts have no place in automotive wiring.Click to view attachment

96 is the indicator lamp

Disregard the comment about brown wire in wire nut.

Blew up the photo more - I’m seeing the threaded screw shank that attaches the indicator - not a wire stub. Sorry. Should have looked more closely.

When you pull up on the lever, the cable attached to it pulls open the flaps inside the "flapper boxes" attached to the heat exchangers. This allows air that comes from the engine cooling fan through the exchangers to be pushed into the cabin.

When you pull up far enough, the lever grounds the single wire going to it. This completes the circuit through the electromagnet of the heater blower relay, sending power to the heater blower. This runs the blower, pushing warmed air into the cabin even when the engine is at idle and the cooling fan isn't blowing much air.

The little bulb, as already mentioned, gets power from the instrument illumination circuit (some years that's power that's gone through the dimmer; other years it does not go through it) and the ground is underneath with a loop going onto the bottom of the mounting screw.

--DD

Going to re-post this photo that @dion has over in FS/WTB forum of the backside of the switch showing the ground connection on the backside that gets attached to the ground wire via the retaining screw.