Hello everyone, Thank you for your replies. First of all, I found the correct relay for a non-a/c from Ames Performance. Part No. # FM366V for a 1978-1980 Blower Cut Out Relay, 4 Terminal (RE).
While inspecting the wiring, my mechanic informed me that something was wrong and that he had to rewire this harness around the blower switch. He told me that he straightened it out and now it works. He said that he included a 25 amp fuse to the power line to the blower switch. He said that I was losing ground to the relay so he added a wire to ground. He now states that it works fine now.
And yes, there is a 3 prong plug that connects to the relay. 2 prongs are vertical and 1 is horizontal. There is also another prong separate by itself and this is the connection to the rear window defogger switch.
And yes again, I happen to have an extra interior wire harness from an A/C car and it did have this relay next to the glove box. So I guess, all cars have this relay.
I'm looking forward to having heat again in my car!