Originally Posted by weedahoe

You are going to need a standard SPDT 5 pin relay if it does not come with one. You will also need a 5 pin harness if you can find one but if not then get some INSULATED female spade connectors. The relay is a 30/40 amp (depends one how you wire it) and can be found at most audio shops and aut parts stores.

This will help pretty much no matter what compressor you have

http://www.viaircorp.com/OnRoad/Sche...singlec_wd.pdf