need help on underhood wiring

i need a good source for aftermarket add on's that will come on and off with the ignition key that can handle 30-40 amps. i can get relays and run off the batt/charging system, but other than the breaker box , which i don't want to mess with, i don't know what is a good hot wire that can handle the extra load. advice from a megawatt stereo buff might have a clue, or any help is already appreciated.
thanks.

What are we working on? Year, Make, Model, Engine?

What are we working on? Year, Make, Model, Engine?

i installed a flex-a-lite model 210 dual puller fans and removed the clutch fan, and it helped more that i imagined. the problem is i'm o.k. as a driveway mech., but i have screwed up more than one vehicles tapping into the wrong wires to get aftermarket things to come on and off with the key.
i'm working on a 2001 gmc jimmy 2wd 4dr, 4.3 v6 w code, a/c hypertech 3 street settings, k&n fipk gen 2, jet mafs. i am also installing a pusher fan, flex-a-lite 112 to push from the a/c core side, as it turns out(sales people say oh this is the perfect part for your truck, but as soon as i had tech support on the phone, he told me they get alot of calls from s. cal, s. fl, tx, etc, we should have bought the bigger fans!!!), the model 210 doesn't cut the weather once the temp hits 80-90, hi humidity and stop and stop trafic here in the capital of south america, miami, fl. what i need is a good source to tap to have the 112 pusher fan come on with the key, and power to the 210 puller to come on with the key, but the 210 is an adjustable thermostat, so it will actually come on when the temp setting is met. right now it comes on at 180-185. i was going to run the off batt/charging system, with relays, but need help deciding what type of relays, and where to tap in. any help would be appreciated.
excheezhead
hope you can help.

In the underhood fuse panel there should be a vacant terminal that is hot in the start and run positions. If not, the fuse marked "B/U LP" has a pink wire to it, and will handle relays with no problem. That circuit is used for the back up lights only and is protected with a 25 amp fuse.

You must use relays rated high enough to carry the current of your fans. These relays typically have 5 terminals and are available at any auto parts store for under $5.00 USD. They are rated at 30 amps. The coil to energize them requires less than 3 amps. The schematic for the relay is stamped on the case of the relay. For terminal #30 on the relay, you'll be best to go directly to the battery using a 30 amp inline fuse.

In the underhood fuse panel there should be a vacant terminal that is hot in the start and run positions. If not, the fuse marked "B/U LP" has a pink wire to it, and will handle relays with no problem. That circuit is used for the back up lights only and is protected with a 25 amp fuse.

You must use relays rated high enough to carry the current of your fans. These relays typically have 5 terminals and are available at any auto parts store for under $5.00 USD. They are rated at 30 amps. The coil to energize them requires less than 3 amps. The schematic for the relay is stamped on the case of the relay. For terminal #30 on the relay, you'll be best to go directly to the battery using a 30 amp inline fuse.
thanks, i'll let ya know how it went, i got mid week days off so wed/thurs. i'll be deep init. i forgot to ask but i also posted for help getting the grill off this same truck without a chain and dynomite. i've looked it over very good, and see some clips, but the rest is a mystery. can ya help with that one?
thanks a lot for the help.
excheezhead