You know relays are a pain in the butt sometimes but they are a fact of life when working with machines and automotive electronics. I've just used the standard relay type of hookup which just outputs a 5-30amp load 12V signal when 12V is applied to the relay from a switch. But when I wired my Adaptronic ECU to run my engine I needed to figure out how to wire relays to output a 12V load when activated by a
negative signal from the ECU. What a pain in the butt. I already had a couple relays that had a pre-wired block that they plugged into. This means I would have to remove the spade connectors from the block and move them appropriately to the relay position so that it would work with the wires that I supplied to it. Not fun and time consuming as well.
I had a couple of friends give me advice on what to do but they even got lost in their own words when they were explaining which wire to connect to which plug terminal. So I studied some website diagrams that just explained HOW the relays worked but they didn't tell me which wire to connect to which input output on the relay! Frustrating.
Then I asked a friend of mine that has a ton of professional audio video installation experience. He said, "oh no problem I'll print it out for you right now." He went to
http://www.the12volt.com/ and there it was! The Holy Grail of relay wiring diagrams!! This site has a TON of good information that can help any normal person wire all sorts of electronics. I am very happy to be passing this information on to everyone reading this. Here is the wiring diagram that showed me exactly how to wire a relay for a negative pull signal to output a 12V load to whatever accessory you are meaning to power.
I basically needed to convert polarity to power my 30AMP radiator fan with a negative signal provided by my Adaptronic e420c computer. I selected "relays" from the top menu of the website and then clicked on "converting polarity" to bring me to these instructions:
http://www.the12volt.com/relays/page1.asp