Original 1970 LS-5. Blower will not work.I installed new relay on firewall. Asked for a/c type. Can I tell externally if correct one? Hooks to wiring harness correctly. With engine off, ignition on, blower doesn't work. I have a full 12 volts at orange terminal coming in. No voltage coming out at other terminals. With blower switch in high, I still have no voltage at blue terminal. I have checked ground at relay and is good. Blower is also new item and will work when wired directly. Blower has never worked since bought car. What is my next step? I have not tried with car running. Should this be done? What's up?