Heater box resistor missing

When I bought my 65 Mustang coupe there were several bonus items that came with the car . One of them was a new heater box and new seals. I was getting ready to install it in the car and noticed that there was no resistor on the box where one should be. It doesn’t even have holes to put one on. Can I just use a cutting bit and make one? I would also have to drill 2 screws for mounting holes. By the way does that resistor connect to anything on the inside of the box? From pictures I’ve seen it doesn’t look like it. What does the resistor do anyway? By the way it is a later 65 so it has a 3 speed switch.
 
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I'm working off memory from years ago here so I apologize if I get something wrong. On my 76 Bronco and my dad's 65 mustang they both had two speed heater fans. In my bronco the resistor broke and I couldn't just buy a new one. Couldn't find one for sale. At the time some electricians friends helped me fabricate a replacement using wire. I dont remember the wire type. It wasn't just copper. What we made ended up just being wire coiled up in enough tight loops to provide the proper voltage drop. This then mounted to the heater box with the coils inside the box. They get hot when in use so this kept it away from everything and the air moving in the box helped keep it cool. There were blade connectors sticking outside of the box for the wiring to attach to.

The wiring harness for the heater circuit allowed the speed control switch to either send current straight to the fan, high speed, or through the resistor, low speed.

In short the resistor didnt hook up to anything in the box. It was just mounted on the box.

Did your car come with a heater? If it didnt you might have to find a wiring harness for it.

Again, I'm no expert on this. I hope this helps you out. I have limited internet access at the house but when I get to work tomorrow I'll try to find a picture of what I'm talking about.
 
I found this post in the classic mustang area.

Heater Resistor--1965 | Mustang Forums at StangNet

Is this the resistor in question?

c2oa18591a_1.364.jpg


I also found this wiring diagram. It's in the thread that I listed above. This is a diagram for a 3 speed fan, but it should give you a good idea of what is going on.

FanSwitch.jpg
 
no it's not wired to anything inside the heater box, I think they just decided to keep the resistor coils inside for simplicity's sake... maybe to keep them cool. the connector from the wiring harness goes on the non-springy side