Fan Switch Help, How is this wired? Options

[Mowog4]

I know this is an amazingly stupid question, but how does this switch get wired?


The three wires off of the switch run to the fresh air blower motor, and the brown wire is the ground. Where does the 12V+ attach to?

[BeatNavy]

Not 100% sure what the question is at this point, but:

All the brown wires to that assembly are grounds. IIRC, the only hot lead going to (or near) that assembly is for the light to let you know you're on one of the blower speeds (I, II, or III) and not just opening the baffles in the blower housing. So basically:

1. Top lever all the way to the left means baffles should be closed preventing air from coming through the vent from high air pressure area above grill while car is moving.

2. As you move lever to the right, baffles open allowing some air from that high pressure area through the vents.

3. You move the lever further to the right and it grounds the first (I) wire which does two things: grounds the light in the dash at the assembly (so it lights up!) and provides a ground path for the blower motor upfront. So now you're also pulling air through the vent with the fan.

Settings II and III increase fan speed. I believe 12v is supplied directly to the fan motor (as Tbrown said), but that circuit is not grounded until you move that lever to one of the 3 settings and provide it a ground. There is a resistor pack in the fan housing. The I fan setting routes ground through the most resistance. The III setting routes it through the least, so the motor gets more power.

Convoluted answer, but that's my recollection. Someone correct me if I bollocksed that up. Here's a picture of the resistor pack in the fan housing.



and here's what that looks like from the outside of the housing. You can see where the 4-prong connector attaches. So the wires at the switch assembly should have continuity to one of these prongs through the connector.