If you haven't purchased any components yet.
If your Mitsubishi still has the original OEM (factory) wiring loom, then the newest method of connecting an aftermarket head unit (i.e. Clarion) is by using a 'snap-on' adaptor harness which eliminates the need for any cutting/joining/soldering.
The adaptor you want is the Mitsubishi-to-Clarion type: one end of the adaptor has the Mitsubishi (female) plug and the other has the Clarion (female) plug.
These adaptor looms can be purchased from most automotive accessory shops, or you can purchase very cheaply online from Ebay.
Check this link (this is the Clarion MAW2-16 adaptor for 1995-2004 Mitsubishi vehicles) @ USD $1 + $11 shipping (Note: the Year of your vehicle will determine which harness you require):
the hard way
If you REALLY want to do it the hard way and start cutting wires, then here is the wiring colour codes:
EARLY MITSUBISHI AUDIO CONNECTORS:
LATER MITSUBISHI AUDIO CONNECTOR (SINGLE TYPE):
I trust this answers your question? :-)
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