I've got an 04 WRX

I plan on removing the gauge cluster and using only the AIMsport dash that I have.

Will removing the dash cluster affect any of the cars basic functions.

The most critical thing I see is that some apparent 12V circuit goes through the cluster for the airbag. I'm not sure if it's just a warning light though of if it actually is more important.

Anyone know about that or anything else critical?

Yes, the charging circuit runs through it also. The alternator will be disabled without a mod being done for that. I think there is a speed sensor circuit in there also. The cluster has a lot of things going on inside it.

For the alternator I see a 12V that runs through a bulb and then to the alternator. Guess I can just wire in a bulb for that. I wonder if you can just tie the 12V in to the wire that goes to the alternator. Hard to tell from the wiring diagram how that all works.

The lead needs to come from the ignition switch through the charge warning light and then to the alternator.

Any idea what the "airbag circuit" actually does?

It's fed 12V and then goes out to the airbag control module.

I assume it is there just to provide control of the warning light when there is a problem detected but no details of the circuit are provided. You would have to most likely look inside the module and trace things out to be sure.

I did actually trace out the circuit. The "stuff" inside the airbag circuit are some resistors, caps, and there's one device that's got 2 inputs and one output... or vice versa.

Is there anyway to test airbag functionality with the cluster removed w/o blowing it up in my face?

If there is a way to test it I don't know what it is.

Hmmm, well I guess i'll just have to figure it out. I'm used to trying things out on my own.

My current idea is to hack out the connectors and the Airbag circuit portions of the board... resolder the gnd and 12v connectors and let it function as it did before.

For the initial version i'll just be putting a diode across the 12V in to the combi meter and the BW that goes to the alternator. I think that should result in proper operation of the charging circuit. If not i've got a 12V LED to mimic the STI cluster wiring for the battery light and alternator circuit.