Are you sure the bulbs in the flasher sockets are incandescent bulbs? If they are LED bulbs, they will be on all the time until you take the warming resistor out of the circuit.
If they are incandescent, what happens when you go into solenoid test? Do they get brighter when they are firing?
Confirm you have #89 bulbs in there. Take the bulbs out and look around the sides and bottom of the metal base for numbers printed or stamped.