[Lil bastard]

Clearly there is a short somewhere. If you have a multimeter, you can pull the Fusebox (4 screws after removing the cover plate) locate the Spoiler Switch, pull the conectors from it and attach the multimeter leads. Set the multimeter to continuity and look for continuity only when the switch is depressed, this is a likely area for the circuit to short, either internally in the switch, or perhaps the connectors have touched each other, or part of the body or other component, grounding to earth.

Then, it's possible that the relays themselves have shorted internally. More difficult to test for this, but replacement is cheap, so I'd just replace them.

The spoiler motor too could be shorting internally. Exposing it by removing the trim in the trunk and again checking it's leads with the multimeter for continuity is the check here.

If these don't cure your ills, you'll need to trace the wiring to be sure that it's not chafed anywhere causing a short.

One thing, be cautious driving over 70mph without a properly functioning spoiler, the rear can get squirrelly with little warning and could be unsafe. Good luck!