Do any HU's have the abilty to switch between HU's internal amp and the preout for amps?

Do you mean so it does not run the speaker outputs at all? If yes, not on mine, but I don't run anything on the build in amp anyway. I run an Alpine iDA-X100M unit.

Yeah, there are. Off the top of my head, Im not sure which ones do now, but they are out there.

What I want is to be able to at the HU is to switch between using an amp for the cockpit speakers/sub and the internal amp for cabin speakers. I guess I meant to say the remote turn on lead, not the preouts.

I put a 6 pole toggle in the remote turn on lead in the Fountain to do this, that also switched on/off 1 lead of each of the 4 cabin speakers. Trying to avoid all this.

Thanks

Never seen one that controls the remote turn on lead. You can get zoned head units that will control what ever your "zone" is. For instance, zone 1 is your cabin speakers and zone 2 is your cockpit speakers. Turn down zone 2 and only zone 1 plays etc...

I have my cabin speakers running directly off of my reciever from the wires which are for the front speakers. The 4 RCA jacks are run thru the amp.

I also ran the blue (amp turn on wire) to a switch on the dash so I can only power up the 2 amps when I want to jam. It plays pretty well w/out the amp, saves battery power and allows you to talk.

Pioneer DEH-6500 1x 1000 watt and 1x 600 watt amps

An idea could be to get a good cheap amp to run the cockpit speakers of, and then just run the cabin amp from the rear channels and the cockpit amp on the front channels. We've done that on a Formula 310BR but wilh a cockpit/swimplatform spilt. Worked well.