This will happen if you have not removed the warming resistors from the flash circuit.

But...with flasher LEDs you still may need to make an additional mod:

The warming resistors pass a little current through the circuit
all the time. But LEDs only take a little current to get running so they
appear on all the time. By removing them, you are killing the warming
circuit as desired.

However, you still need a little resistance in the circuit for the circuit
to work. The LED bulb alone is too high of a resistance to cause the
circuit to work... so you have to put the 100ohm or 1k ohm across the LED
terminal to make the circuit work complete."

Hmmm. OK appears not because of the LED flashers then.

I just noticed a possible clue.

You said the flashers are coming on with the A/C relay selected. You also said you replaced the snubber boards and flash lamp boards. What I have noticed in your last post is you say the lights are coming on when the coil test enables the A/C relay. Nothing visual should happen here, all that should happen is that you hear a click of the A/C relay in the cabinet.

When the relay clicks, It puts power on "C" for the flashers. In test mode, the flashers should not be coming on, because the transistors should be off. In coil test, too...when those coil tests are run, the A/C should be on the "A" side for the coil only when the solenoids are fired. Somehow, the flashers are also simultaneously getting power.

I'd be taking a closer look at the A/C relay board. (miswired? shorted?)

145484.jpg

Only the A/C relay board. It is wired this way as a power selector. If you look at the diagram above in the thread, the tab labeled ground is connected to the common points on the relay terminals. This way when Q7 goes low and makes conduction through the relay coil, it routes power through the other set of contacts.

The snubber boards are typically wired this way, allowing a drive transistor to control a higher power coil. In this case, the ground labeled tab is actually connected to ground. They could have made a second silkscreen for when the board is used as an A/C relay configuration, but it wasn't that important.

145406.jpg

The ground side of the 330 ohm resistor on the flasher boards.