I have a 1980 Firebird Esprit. It had AC at one time, now it does not. Some parts are there but more missing than what is there. Inside the car, all I have is a fan switch (all other levers and controls for ac and heat have been removed from the panel). Under the hood is the blower (brand new), blower resistor, and a blower relay. I have no wires to any of these three devices. After much research I drew the attached diagram. I tested the switch with an ohm meter and figured out which terminal does what. I tested the resistor with an ohm meter and it seems to be working. The relay reads nothing on the ohm meter. I will replace that.

Blower Switch:
4 terminals
3 position lever (Low, Medium Low, and Medium High).

Blower Resistor
4 terminals (low, medium low, medium high and a power out to relay)

Blower Relay
5 terminals (**I do not know which terminal does what or what color wire below connects to which terminal)
I do know that:
Red wire is for power from alternator and a fuse
Black wire is ground
Orange wire is switched power (I'm assuming it goes back to the blower switch)
Dark Blue wire carries varying volts from the resistor)
Purple wire power to Blower

So my questions are:
1) How do I wire up the relay (which terminal connects to which wire)
2) I understand the blower is ALWAYS running on low. Blower switch inside car has only three positions (L, ML, and MH). Somehow, the relay makes Blower run on High. Shouldn't there be a switch or something to make it run on High?

 

Can I skip the relay altogether and Just run the dark blue wire from the resistor to the Blower? This would give me Low, Medium Low and Medium High. I would not have a high.

I just don't understand how the Relay knows when to "cut out" to run on high.

 

Some more photos

 

So I need to figure out what wires got to 1,2,3,4, and 5

 

Did a bench test last night with the old blower. Worked fine on all speed (L, ML, MH, and H) Skipped the relay altogether.