your definately missing a 12v supplt to both of them?

if thats the case, sounds like there is a wiring fault somewhere.

I havent really played around with sierra's the ones i know like the back of my hand is escorts/orions. But manufactuers generally have patterns to the way things are wired. There could well be a fuse or relay gone, things like the coil are usually switched via a relay, so it could be a relay is burnt out, or possibly just a fuse popped?

Have you checked these yet? If not check these and get back to me?