Deane:

What relay are you using?
What is the the motor?

Some SSR bricks designed for this purpose have 3-32 V for an input and no series resistor is required. A heat sink with the appropriate thermal grease is. They have to be triac or back to back SCR's.

Some offer to switch at zero current. It should be random.

Some require series resistors.

Some SSR's are triacs, dual SCR's, SCR's (won;t work) or MOSFETS (won;t work).