AC Fan Speed

[mike561]

I noticed that when i switch on the AC it only blows when the switch is on high, none of the other speeds work, it just shuts off. i tried putting on a different switch and it still did the same thing. theres no freon in the system either, i was just checking to see if everything else worked. i wonder if its the blower motor resistor or something. if so, wheres that located???

[mike561]

Ok, i found where the resistor is located, i took it out to inspect it and it still looks good, though i dont really know what to look for. i took some pics to show what it currently looks like. also there is a plug that i saw today just hanging not plugged into anything and i cant see where it could fit into also, its right by the blower motor as well. i got a pic of both the resistor and plug. hopefully someone can help me out, thanks. heres the pics:

[GreyGoose006]

i believe that in some systems, there is a switch to prevent the ac from working if there is no freon/freeze12/whatever in the system because the freon ect. is the lubricant for the pump, so without any, the pump will kill its self.

what happens if you put it on economy or vent (cant remember exact setting off hand)

mine has no freon in it, and i just use the economy vent setting.
works well enough for me.

[mike561]

Yeah theres no freon, and i can see the compressor clutch isnt engaging. the fan speeds arent working on med or low, just high. i would geuss no freon would'nt have anything to do with the fan speeds.

[silicon212]

Perhaps the problem is the speed switch itself, have you looked into that? Have you checked voltages coming off the switch or going into the resistor grid? High speed uses a different fuse, have you checked all of the fuses?

[Blue Bowtie]

The basic possibilities are the high speed blower relay, the blower switch, or the resistor array.

• The new switch should have solved that potential problem.
• The high-speed blower relay has N.O. contacts which power the blower directly from the battery. SOME (mostly later) years used the N.C. contacts through which power for all other speeds is routed, and some used a parallel feed from the resistor to the blower motor. If your's is the former, measure voltage at the N.C. contact of the relay at lower speed settings to verify whether the speed switch is functioning.
• The resistors frequently suffer from poor connections, interrupting voltage under load. Make sure the blower motor is connected and probe the resistor connector at various blower speed settings to verify whether the resistor array has continuity.

The different years should have looked like this:

[mike561]

ill check into all of this, and let you know how it goes. thanks for the diagrams too.