Planning on adding some gauges to your WRX? There are several methods to get the proper voltage sources to get the job done, but just using the wiring harness for the clock is the simplest in my opinion. It has all of the voltage sources you need, and it is a great location. This is especially if you are planning a gauge pod in the clock’s spot, or cluster bezel. On my ’05, I personally used the SMY ClusterMaker Dual Gauge Pod 52mm that replaces the factory cluster bezel. I personally like keeping my clock and don’t favor the look of having the gauges on the a-pillar.
I spliced right into the wires I needed and soldered in the power harness for the the boost gauge I was installing. Before buttoning everything back up, it is a good idea to make sure everything is working as expected.