1981 Corvette w/350 - So I've just about got everything wired up, vacuum lines run and tested the Ac circuit. Everything works as described as in the below table from the 81 Vette shop manual. Only issue I have, is the lack of blower in the AC "Norm" position. No blower at all - simply shuts off. I have new relay, new AC controller and new vacuum lines all the way around. All the vents and actuators are acting right and airflow is correct.



So I figured next step is to start ringing out wires from the AC Controller and Blower switch to the relay and resistor. That's when I find something different. The elec AC schematic from the same manual shows two orange wires on terminal 52 (1 to blower switch and the other to the relay) I don't have those wires. I also find there should be another brown wire from the controller to the resistor for 12v - I don't have that either, only the incoming 12v from the fuse panel. I will confirm tomorrow, but I am assuming there is 12v on the resistor, just coming from somewhere else.



But, this brings me to another issue - I only have the three connections on my AC controller - 2 Green (confirmed one to pressure switch, the other to idle stop), 1 brown from 12v fuse panel and 1 yellow to blower switch. Do I need the orange wires connected as described in the schematic? I guess I have a missing orange wire in the harness somewhere? I don't think I've seen a photo of a connector with the orange wires? Anyone else have them? My connector below...



Otherwise, the wires and corresponding colors at the resistor and relay connectors (according to the schematic) appear to be correct. Relay below...



the Resistor connector...



So, in general, everything minus the orange wires at the controller, seems to be correct. If I in fact need the orange wires, do I need to change out my ac controller switch and connector? Mine is a three terminal switch and connector...



I've seen the four terminal switches such as this one - it this what I need, and what about a 4 conductor connector?



Could use a bit of advice and guidance on this one. Am I missing something? Hate to start chasing, hooking up wires and swapping switches just to cause more issues. Any advice, tips or suggestions is greatly appreciated....

 

Here is a diagram for a 77. The max setting only gives a high speed blower not adjustable like your chart.
Maybe it will help

 

This is what I see using the Willcox Corvette 1980 electrical troubleshooting manual.
1. Circuit 50 (brown wire) feeds the controller head. Circuit 50 also lands directly at the LOW speed portion of the blower resistor (blower fan runs LOW speed when blower switch is in LO position).
2. When controller head is in the NORM-VENT-HEAT-DEFROST position you are sending power to the blower switch Circuit 51 (yellow wire).
You have Circuit 50 (brown wire) power...Check
You have all other functions of the controller switch EXCEPT in NORM position.
Try this...
With the controller electrical connector removed, at the controller switch itself where brown wire would land and where the yellow wire would land move the controller slider to the NORM position
Do you have continuity between the 2?
If not your controller switch is defective.
4. Circuit 52 (orange wire) only energizes the coil of the high speed relay when blower switch is in the HIGH speed position. I don't see the need for a 2nd orange wire like your drawing shows.

 

Here is something else you may think about in the near future...
Replacing the 2 housings M & F/M sides before they melt into a solid ball and you cant remove the wires to replace connector housing.
We all have seen these connectors melt before, not to worry yous is not unique they just need replacing.
Is it a 6 cell or a 8 cell wire connector?

 

Here is a updated drawing, no charge...

 

Thanks Guys -

BMoto - OK, so had a few minutes at lunch today and did some more digging. Long story short, you are correct in the loss of continuity between 50 (Brown) and 51 (Yellow) in "Norm" position. I have continuity in every position but "Norm". Seems odd to me as this is a brand new switch, but....

On another note, I did check for continuity on all other wires in the circuit - all appear to be good, and yes the 12v supply to the relay is present, just not being supplied by the 12v from the selector switch. So, another selector switch seems in order? Any idea at to which one (whether the 4 post or 3 post) is required?

On the housings, yes it is pretty bad - it is a 6 post connector - any idea as to where to get one without having to purchase a whole new wire harness?

 

Your connector for the controller is marked A-B-C-D-E you have wires landed in A-C-E.
It doesn't matter 3 or 4 post switch will work, you are only using 3 of the 5 connector cells anyways.
I updated your drawing above. The ORN wire to the coil of the HSBR is from your Blower Speed Selector Switch, when you select HI it energizes the relay coil.
Now on that 6 cell connector housings, that looks really bad now you took a decent photo of it.
Those connector housing is done! I would replace both Male & F/M housings.
It is carrying the load from the alternator and also feeding the fuse panel, and also is the start circuit to the starter solenoid.
Here are the part numbers for both M & F/M 6 cell connector housings.
Male GM #2977042
F/M GM #2977044
There are 2 vendors I purchase my housings and terminals from.
​​​​​1. E-Bay: Both Male & F/M housings with crimp terminals free shipping LIINK:https://www.ebay.com/itm/37275847720...IAAOSwoPBdcABg
2. Mouser Electronics:
Shipping is extra with Mouser
F/M #2977044 $1.02ea LINK:https://www.mouser.com/ProductDetail...OKxdR4RA%3D%3D
Male #2977042 $1.12ea LINK:https://www.mouser.com/ProductDetail...6Hs0gUEg%3D%3D

 

Try this,
Controller Switch housing marked A-B-C-D-E
You are using A-C-E right now...
C = Circuit 50 (Brown Wire)
A = Circuit 51 (Yellow Wire)
On the switch itself with connector removed see if you have continuity between C & B in ALL selector switch positions NORM-VENT-HEAT-DEFROST
You may just need to move the yellow wire to cell B if all above is true.

 

Yep, thanks for the links to connectors...will order new.

As far as checking continuity between C and B - it won't read at "Norm". Didn't notice it til today when digging, but both B and A are the same tap. You can even see it in the photo, the two tabs are joined near the switch. A is B, vice-versa. Ordered a new switch - we'll see...

 

This problem was in fact solved. It was as simple as a defective switch. Replacement of the switch corrected continuity and blower functions in norm. Thanks for the help!