The RCM is a circuit board with mounted relays.
It is in the box by the battery closest to the engine.
It has about 5 harness plugs connecting it.
Remove the negative battery cable before pulling it out and unplugging it.
It's not easy, but the plastic cover comes off and you can inspect the solder points with a strong magnifying glass.
Lately there have been several that had open relay coils.

DJ ( tighed1 ) can figure all this out for you, all you have to do is send it to him along with some beer money.