I have a 69 with an A/C problem. Everything works fine on Low speed and the next two. But on high speed the blower will not run. After researched I have traced everything down to that's its the blower relay bad or its the wiring is incorrect. I enclosed a picture of the wires on the relay on my car. In the assembly book it shows 4 wires. I think I need a ground wire on the number 4 post?