bcashJMU

Hello,
I know this has been done many times and talked about but for some reason I can't get my primary fan to come on...i haven't even started messing with the secondary yet. I am trying to put my fans on manual switches. I have a t-connection from the green/white wire out of the primary fan relay (F position on the relay)...that wire I have plugged into the ACC prong of the switch. The ground prong is wired to a body ground. and I wired the positive prong to a BATS opening on the fuse box. When the car is off and i turn the switch on, the LED lights up but the fan won't turn on...I figure this is normal. However, when I turn the key on, the switch no longer lights up nor does the fan turn on. Any ideas where I have gone wrong? Should I use a different voltage source? I have attached my wiring diagram in case my explanation was a little sketchy. Any help is appreciated.

bcashJMU

My main goal is for me to be able to have the fans turn on whenever I choose without messing up the factory thermal settings. I have read a lot of threads on here and Willie's dual fan article for help, but for some reason I can't get it to work.

deadbird

LED rocker switches light because your using the +12v to the source to also light the LED.
Ground - negative for LED
Power - +12v from fuse panel/battery
ACC - switched +12v to the source (fan/lights/relay, etc)

You're only controlling ground to the relay. I'd be surprised if the LED would work wiring it with the polarity backwards.

GND - +12v (acc fuse, etc)
Power - chassis ground (-12v)
ACC - to grn/wht relay wire

That will at least make your fan run on demand.

85Z28NOS

iTrader: (2)

The computer controls the fans by grounding the relay to close the circuit. All you have to do is run a wire from one side of your toggle switch to a ground source, and from the other side of the toggle switch to the fan relay terminal(B). Just splice the wire with the existing wire so the computer will still control it when you dont override it.
FYI-if you do this to the second fan relay it will automatically turn on both fans

bcashJMU

I tried reversing the polarity and it didn't work.

What prongs do I use, 85Z28? I have three, not just two sides. I am new to switches and a novice at wiring, so I need detailed instructions haha. Any pictures would be helpful, but schematics don't help unless they are explained in good detail like which voltage sources are best to use and whatnot.

Base91

iTrader: (1)

First don't use the led switches. Get a couple of 2 prong switches (one for each fan). Splice to the grn/wht wire to one side of the switch. Ground the other side. This will work with the ignition on. If you want to have the fans come on even with the ign off then you need a permanent supply to the relay. Just find the power wires and splice in a supply but it's more work. If you want a light get one and wire one side to the power wire that goes from the relay to the fan motor. Ground the other side. I think this is the easiest way to do what you want.

bcashJMU

Ok, I first jumped the two thick gauge wires in the primary relay and the fans come on...did this to test the relay. I then spliced the green/white wire and ran it to the acc prong on the led switch. I grounded the ground prong and ran the power supply to a fuse slot that is active only when the ignition is on. I turned the key on the switch didn't work. So I did what was mentioned above and reversed the polarity by running the ground to the acc prong and running the splice to the ground prong. When the key was turned on, the switch lit up when turned on but the fan wouldn't turn on.
Is there another way I can wire these that will take the green/white wire out of the scenario? Maybe a jump wire between the two thick gauge wires with a switch in the middle of it?

bcashJMU

Ok I spliced off the signal wire of the secondary relay and the switch and fan are working. However the led on the switch is lit when the fans are off and goes off when the fans are on. Anyone know how to reverse that?

Base91

iTrader: (1)

The green/white wire is the relay 'trigger' so that's the one you should ground to turn the fan(s) on. You should not use a switch to switch the the big wires as the carry a higher current and will burn out the switch unless it's a huge switch. That's what the relay does. The small, low current, wire activates the relay and the internal heavy duty switch handles the higher current. You keep talking about wiring the switch to a power supply. I'm not sure but if you do it wrong it may feed power to the ecm and screw it up. You don't need another power supply. The grn/wht wire goes to the ecm and the ecm grounds it to turn the fans on. I don't the wiring of the led switch but it may not even be compatible that's why I didn't even try. Separate the switching and the light functions and you have two very simple things to deal with that don't affect each other.

ASE doc

There is a reason why cooling fans are automatic. Whenever the engine is running, it produces heat. Historically, mechanical fans were used. Engineers realized that by using an electric fan, they could increase efficiency by having the fan run only when the thermostat was open and thus hot coolant flowed through the radiator. The electric fans are automatic so that they work when the engine needs them in order to limit heat.

By replacing the automatic control with manual, you are taking responsibility for managing the engine's temperature. Since the factory temp guages are notoriously inaccurate, you really have no way of knowing when the engine needs the cooling fans. Even if you could know, you may not always be aware, as you will be busy driving the car.

Manual switch controlled fans are a half**s way to avoid spending the time and money to either repair the factory system or simply replace it with an aftermarket fan controller.

bcashJMU

Thanks for your input but some of us can't afford to put in an aftermarket fan controller or have the time to fix the factory system. I have left the factory system alone and have just Installed an override switch to turn them on when the factory system chooses to not work. I also wanted to have them on switch for autocross. So I can keep the fans going while I am waiting in between runs with the motor off. i have it working so I am satisfied.

bcashJMU

@base91: for some rwason my green/white trigger wire wasnt working, so I splice off of the secondary fan trigger wire and now it works.

bcashJMU

ok so I have everything wired and it works great. But now every time I turn the key on, the 10A fuse for my gauges blows instantly. Any ideas as to why?

Base91

iTrader: (1)

Hate to say it but if you've now got a fuse blowing you probably did something wrong. Not sure what you mean by secondary fan trigger wire. A wire other than the trigger wire or the trigger for the secondary fan? But it sounds like whatever you did is causing a short. When you say grounding the trigger wire didn't work are you talking about with the key on? Were you using your switch? Are you triggering the relay with your switch or did you splice it into the fan power wire. There are several ways to do the override. Some elegant, some not so much and some plain wrong. I'd go back to the start and understand the circuit. It's not clear now what you've done.

one92rs

iTrader: (5)

why not get a good aftermarket controller such as flexalite controller to control the fans and never look back.

ASE doc

For the time you spend and the frustration of dealing with these switches, just to risk a severe overheat anytime you forget to turn the fans on, you can buy a Flexalite controller for about $40. Youn can always install a switch to run the fans manually, in parallel to the controller.

For anyone working on your electric cooling fan circuit, I have uploaded diagrams to an off site forum. Find the link in my "wiring diagrams" thread on the Electronics forum.

camaronewbie

Read and wire according to my post #2 on this thread: https://www.thirdgen.org/forums/cool...ctric-fan.html

You really have to use relays for fans - your blowing your fuse because your wiring is off and your drawing fan amperage (like 20-30 amps) through a 10 amp fuse.

But I agree that a seperate fan controller is much much easier, as you'll need to duplicate this for each of your dual fans - which means 2 relays at $8 a piece, 2 switches at $3 each, and the wiring (a 10gauge roll and a 18 gauge roll) about $8 each, plus connectors, and your time/trouble. That equals $40 right there!

Base91

iTrader: (1)

All true but if you want to use this as a learning experience you need to learn some about how relays work and how the circuits are laid out, what's powered with key on/off and what's grounded and when. Learn to use the voltmeter for voltage and resistance etc. etc. Then, based on understanding the circuit diagram, do whatever it is you want to do. You might get lucky but you can't make assumptions and swap wires and guess. Doing it yourself can be fun and save money but not if you burn something out. Good Luck.

bcashJMU

I got it all working today. Apparently I didn't need to use the power supply prong. I just have the ground and acc prongs being used right now and it grounds the the trigger wire when turned on. It works really well. Thanks for the help guys. I will eventually install a controller later on, I just don't have the money right now. I got the wire from dad while I have been at his house. All I had to buy was some connectors and two switches. It was less than $10. Thanks again for all the help. My fans still work normally under the factory settings, so even if I forget to turn them on, the temp sensor will trigger it to come on...so no worry there. I just wanted to be able to turn them with the motor off to cool the motor down in between autocross runs.

blackfrontier

iTrader: (1)

When I bought my 87 GTA the fans were already wired to two lighted toggle switches for the dual fans. The primary fan switch kept going out and melting the back side of the switch. For now I had it wired to come on with the key so I know it's always on and I can toggle the rarely needed passenger side fan. It's kind of a short term fix until I can digest all the options to hook it up factory style yet come on sooner. My car runs a steady 220 degrees and driving around town, highway, right fan on or off doesn't change the temp. Thinking of trying a new thermostat., but for now I don't care if the fan comes on at warm up as I just want to make sure it works.