Freefallin

So i just bought 2 nine inch fans to mount in front of the AC condenser of my 04 GTO. Mind you the GTO doesn't come with AC condenser fans.

Basically, i just want to install them and wire them in a way that they will come on only when i switch on the AC.

Any ideas how to go about doing this?

Thanks in advance!

Freefallin

No one?

1 FMF

iTrader: (1)

tap off the wire +12v wire going to the AC clutch. use a 12v automotive relay to then switch power on/off to your new fans. splice off ac clutch wire goes to switching side of relay. run wire from +12v bus in fuse box to inline fuse to load side of relay, 2nd pin on load side of relay wire to your new fans.

see here for what i described for that guy, same thing for you basically
https://ls1tech.com/forums/stereo-el...ch-system.html

Freefallin

First of, thanks for the reply!
Just want to let you know though, as much as I hate to admit this since it never fails to discourage any knowledgeable member from replying, I am a complete noob in this matter...electronics. To give you an idea as to how much of a noob, I had to Google "tap off".

I read your reply over and over but couldn't understand much past "run wire". So yeah...could you please run it by me again in layman's terms? Like a rundown of step by step instruction on how to do this would be awesome...if it isn't too much to ask of course.

Thanks it advance!

eseibel67

iTrader: (10)

It was an indoor recess today cause it was rainin' so and drew this pictchir.

Freefallin

Wow! A pic does speak a thousand words! Thanks buddy!

A little confused about a couple of things:

1) There are two wires, joined together, going to the ac compressor connector...which connects to the compressor. What am I supposed to do here?
Expose a little of the +12v wire going to the compressor by removing a bit of the plastic insulation covering it, then get an extra wire and connect it to the exposed wire, then take the other end of that wire and connect it to the relay...like this I am done with the compressor side, correct?

eseibel67

iTrader: (10)

Sorry. I tired to make the wire in the drawing green, but it didn't turn up just right. There is a green and a black wire going to the compressor clutch, you want to tap into the green one.

Freefallin

Ok! And the black one isn't to be done anything with, correct?

1 FMF

iTrader: (1)

i strongly suggest you google some info regarding automotive wiring, 12 volt wiring, 12 volt DC wiring.
i'm more than happy to give you advice, but over the web i have no way and you almost have no way of knowing if you've misinterpreted info and mistakenly wire something wrong. do the wrong thing and hopefully you only blow a fuse, other things that can happen is the engine dying while driving, killing parts like the alternator, engine computer, and causing fire.

in automotive wiring, it is 12 volt DC, or 12VDC. "ground" is the side of the electrical system that is connected to battery negative and has no power on it in laymens term. the other side of the electrical system is "hot" and is connected to battery + and has power, and if you accidentally touch something that's "hot" and make a direct metal connection to ground then the result is one of things mentioned above.
you never make a connection from the hot side to ground without some sort of resistance or load, or device between the two such as your fan motors. anything that uses electrical power to do work is known as the load, and it has electrical resistance.
if you wire up things directly to the hot side and ground, it runs all the time,
so you put a switch (or relay) in the hot side of the circuit to switch power on and off to the device. google electrical relay if interested,

normally in auto wiring black wires are usually ground wires and they connect to the negative side of the electrical system. wires that are red or of color are usually positive and have power on them either all the time or switched. never assume, refer to the electrical schematic if in doubt. for those two wires going to your ac compressor, the black wire goes to ground so you don't touch it or tap off it.
the green wire is the one supplying power to your ac compressor, it is switched power as in only has power going to the compressor when you turned on the AC via climate control. so logically, if you tap off this wire you now have a power source that is switched, it only has power whenever you turn on your AC. run that to a relay. the relay then acts as a switch and turns on your fans.

1 FMF

iTrader: (1)

also disconnect your battery before you do anything.
hopefully you realize you disconnect battery - (negative) first.
the reason is battery - is ground, and is connected to the frame of the car. basically if you touch any metal of the car, you are connected directly to battery negative.
now if you use a metal wrench and go to undo battery positive while battery negative is still connected, if your wrench touches any metal of the car you have a direct short to ground. your metal wrench has no electrical resistance and you will get massive sparks and arcing, and it is possibly to weld the wrench to the battery terminal or metal it touches that's connected to ground.
hopefully that made sense, and you already knew that. if it doesn't i recommend you not do any wiring until you get a better understanding.

Freefallin

Thanks for the 101 buddy. Well, I kinda have the basics on electric circuit down. I know the hot and ground you are talking about. I don't think I am that much of a noob.

I just wanted a step by step for dummies guide on how to do this particular job. I don't think it would take more than 7-10 lines to explain it. Trust me I did look up automotive wiring. But like learning anything new, its going to take time to fully understand it. I just want to understand it while I enjoy my days in the cool cabin of my car.

Everything you said makes perfect sense. However, I don't think there is anything that would go wrong if I followed the instruction. You know, connect this wire to that, black wire to that, green wire goes there...etc. There is nothing that would go wrong provided the instruction is accurate and flawless. Once I got this job out of the way, I promise I will study up on automotive wiring.

Freefallin

I think I got this. Is the "fuse box" supposed to be the battery. Like the + post of the battery??

eseibel67

iTrader: (10)

No, "fuse box" is 12V ignition switched supply from fuse box. There are usually empty receptacles in the box. Poke around with a test light or DVOM until you find 12V with the ignition "ON".

Freefallin

So what would be the difference between making the connection at the +12V fuse box like you suggested vs. making the connection at the + battery post?

eseibel67

iTrader: (10)

It will work directly off the battery if you choose, just make sure you fuse it.

1 FMF

iTrader: (1)

hey you said you had to google "tap off of"

attached is a pic of the engine bay fuse boxes in a 2002 camaro. it's probably different in your car but the same principle applies. the white arrow shows the stud where they recommend you attach jumper cables, but it is also a great point to attach a ring terminal in order to access get battery power. this terminal is hot all times. you generally can't go directly off the battery terminal because most cars are not easily accessible there, plus when you do it that way it looks lousy.

the second attached pic with red circles is an example of a fuse box in gm truck. the trucks unlike cars are designed for add on's specifically trailer wiring and brake controllers. the red circles shows the main battery feed to the fuse box, one side comes from the battery, then goes through a high amp fuse, then out to other terminals in the fuse box. if you have something like this, then it's ideal to work off of. use a ring terminal and go off the side that's protected by the fuse. run your wire and as soon as possible use an inline fuse that your electric water pump recommends, this way the circuit is completely protected.

be aware that not all things in the fuse box are hot at all times, or are only on when the ignition key is on. and the empty spots in the fuse box you can use, but they don't have any wiring at all to them you would have to pull the fuse box apart to access the underside and wire it up.

in my two attached pics, those terminals are the same as battery +. they are hot at all times.
in the 2nd pic with red circles, the bottom stud with the red wire coming to it is from the battery. the top terminal of those two is protected by that fuse in between the two, it's this one you want to use a ring terminal and connect off of, just undo the 10 mm nut, attach your ring terminal, secure with nut, easy. i also found my pliers, thank you.

1 FMF

iTrader: (1)

wiring diagram attached.

the big question is when do you want your water pump, or whatever the device is, to operate?
the way this all works when wired as described, is when you apply power to pin 85 of the relay this is the switching side. the little coil in the relay activates the load side of relay and makes the connection between pins 30 and 87 supplying power to the water pump.
how you choose to power pin 85 of the relay is up to you.
you can run a hot wire to a switch inside the car you mount somewhere then run a wire back to pin 85 of relay, and manually switch on and off whatever the device the relay is operating.
or you can tap off something in the fuse box that only has power when ignition key turned on, or when engine running. now i was writing this with the other guy in mind who had radiator fans, or water pump **** i forget who had what but it doesn't matter electrically.
now what you can do and i think is a good idea, is find the wire that is the output of the fuel pump relay in the underhood fuse box. it will be the wire from the "fuel pump relay" going to the fuel pump. the fp operates basically only when engine running, it runs briefly when key turned to on prior to start but big deal. your water pump would work in same fashion.
now if you were talking about radiator fans and wanted them to only operate when ac compressor is running, then tap off the hot wire going to the ac compressor. i don't know the colors but the black one will be ground so use the other one. use a "quick splice" to "tap off it" and run that wire to pin 85 of the relay. google "quick splice" will explain that for you. you can either tap off the ac compressor wire near the ac compressor, or if you can trace it back or know where it is in the underhood fuse box then bonus you don't have to run a long wire. mount your auto relay near the fuse box, the bulk of the wiring is near the fuse box, and you only have one long wire run going to the device (water pump or radiator fans or whatever).

Freefallin

Beautiful stuff 1 FMF! With eseibel67's diagram and 1 FMF's detailed instruction, pics and video I feel confident enough to do this sheee

Thanks guys!

Freefallin

Started a new thread but later thought why not put it on here since its the same issue.

Well, I just got done getting everything I need...except for the wires. What size wires do you guys suggest I get for my 2 new retrofit AC condenser 9 inch electric fans?

Mind you, I have no idea what amp my new fans draw since the stupid company didn't bother including that information with the fans. I will be using 30 amp fuse thou. Although I would love to know how much amps the fans draw without having to buy some expensive gadget or going to any place to have them measured, since no such place exists here.
I got a multimeter but it can only handle 10amps.

So yeah, how can I determine what size wires to use? I got 14 gauge wires which is about the same size as the wires connected to the fans, would that be ok?

Appreciate any help!

eseibel67

iTrader: (10)

There is a formula to figure out appropriate wire guage for the amount of amps and the length it needs to run, but I don't know what it is. I just go by what seems sensible.

Cooling fans draw pretty good power, especially on startup. Your fuse box is located fairly close underhood, I would guess that 12g wire would be adequate for the switched-side wiring. On the control side of the relay, 16g is all you need.