Umm, this wouldn't be a Galaxy Saturn TURBO, would it?
That one word "turbo" makes it a totally, totally different radio from the one they sold with 'just' the name "Saturn" on it.
Okay, so if it's a Turbo, you are seeing just how little carrier power is needed to fully drive the internal linear.
If you turn up the radio's trimmer control that sets the max carrier higher, you run the risk of blowing out the linear and/or power supply.
If you forget to turn down the carrier knob before you turn on the linear, you could end up with a 120 or 140 Watt carrier when the linear is turned back on.
Won't blow out the radio right away. Just not a wise thing to set up to happen.
So, just what kind of amplifier do you have that needs a full 4-Watt carrier? Can't see how it matters, since the barefoot side of this radio is throttled back to no more than about 16 Watts peak. That's all the internal linear can handle, so that's how the factory sends it out. Any linear that "needs" a 4-Watt carrier won't be impressed with 16-Watt voice peaks.
We did work out a setup that mounted a trimpot on the side of the linear "suicide" switch. Requires a two-pole, or "DPDT" switch. This trimpot would get placed in line with the trimpot on the radio board that sets max carrier. When low side is selected, the radio's internal trimpot will usually get you 3 Watts or 3 and a half. The trimpot on the side of the switch is shorted by this side of the switch. When you select "high" and turn the amplifier back on, the short across the new trimpot is removed placing it in line with the radio's carrier trimpot. The new trimpot is used to set a safe max carrier for high side only.
Whew! Takes longer to explain than to install it.
I'm pretty sure we have some pics of this solution. I'll see if I can dig them up to post here.
(edit)
Whups, just noticed you said the switch shuts off the fan and the linear both. This means you already have a 2-pole switch. I suppose our 'extra trimpot' trick would require a 3-section switch.
Oops.
73