I know it has been several days since your original post, but perhaps
this will help, if you are still having problems.
Disconnect the 12 volt power to the tuner and then run the light bulb
test. With no power, a correctly operating SGC-230 will pass the RF
straight through to the light bulb. If the bulb lights like it did
when connected directly to your rig, then you know the relays are not
Does your transceiver have an automatic shut down when the SWR is
high? Does it have the capability of putting out about 10 watts even
if the SWR is high? I have this problem with my ICOM 706 MKII.