Thanks for the reply. That makes sense. My wiring diagrams do not show the relay and how it is wired. I guess that's my next issue.The relay is part of the circuit so that all that current that runs through the blower motor on the "high" setting does not go through the switch.
The relay is only present and wired in for A/C cars. The relay is needed for "HI" as the A/C blower motor draws more current then it's HEAT only blower counter-part. If you have a non-a/c car, there is NO hi-speed relay or associated wiring.I am reinstalling the wiring in my car. For the heater blower motor, I know I need a heater resistor if I want different blower speeds but do I need a heater relay or is that just for cars with A/C?