Ian & Eric,
Thank you for the suggestions and help. I apologize for not getting back to you earlier. It's been a busy time for us.
Eric, the Control Unit is separate from the burner unit and mounted next to the Current Regulator. I have the manufacturers technical data booklet (including install instructions).
Ian, as you suggested I removed the duct from the inlet (aft) end and had Peg turn it off and on. The blower did not turn at all. I did hear a distinct "click" from the Control Unit, which I verified by holding a screwdriver to the CU and my ear.
You noted that if a relay was working it was likely not the Control Unit, but may be a PCB at the aft end of the burner unit. Could you give me an idea where to access the PCB?