Added a couple of auxilary fans to my AC condenser to possibly help with my cooling issues because of a front mount intercooler.

I added a relay to run the new fans - where is a good place to tap into for a signal to turn them on?

I considered tapping into one of the power wires on the stock fans but do not want to steal any current from them. Maybe use the signal that runs the stock fan relays?

Where would I find this? Colors / pictures would be great!

Is there a better solution? A solution I think I would like better is to use my fog light switch to just activate the fans when I want (since I do not have fog lights anymore). The wiring for the foglights is in place and terminates in the right area... I only need to make the foglight switch active anytime the car is on - not just when the headlights are on. .

Yes, I'm electrically challenged somewhat.

 

One of the fan relays is triggered when you turn the AC on. You could use that "on" signal to switch your relay or just use the output from that relay to turn on your fan.

Dale

 

^^^ I was really hoping to trigger it with the stock fans or manually since I have a hard time keeping the car as cool as I want it even with the AC off.

 

I am not 100% familiar with how the FC/FD thermoswitch operates but you can probably tap into that for your signal.

If you tap into the factory wires that would work as well the relay draws VERY little amperage for the signal wire.

Do you have a FC thermoswitch?


John

 

I don't think you understood what Dale was saying...

On your pass. fender/shock tower there are 4 relays. Flip them each over to find one/two thin wires and one/two thick wires. The thick wire is what your fan runs off of. And, one of the thin wires is the 12V+ turn on lead for the relay. So....

1) Get a multimeter.
2) Probe the thin wire in each relay and connect the other probe to ground.
3) Turn on your AC while testing each of the thin wires. Once you see a 12V from 0v, that is your AC turn on lead.
4) Splice into that to turn on your new relay.

Also, to clarify, do the factory fog lights not turn on independent? I don't have any experience with them but I do believe Mazda doing something goofy like that. "They are fog lights, if there is fog, then they would have the headlamps on..." :-)

 

^ Was that directed at me?

I understood his post, but why would you want to tap into the A/C relay and have to manually control the circuit if the car is getting hot?

If you go to the thermoswitch or the relay that is activated by the thermoswitch that will automatically turn on the fans. You do not have to watch the gauge (commander) as much. One less thing to worry about.

It does make sense to connect to the "High" fan relay, IMO, only if the car starts to overheat with the A/C on. The OP did not say if that was the case. So I looked for a different option that does not require driver intervention.


John

 

Per the PFC Water temps in hot weather and traffic and no AC on creep to over 100C sometimes. In very hot weather over 105 and sometimes more.

I have a dual oil cooler setup and a Koyo N Flow radiator. I think its my Greddy style knock off intercooler that is overheating the car.

It is my hope that the two 12" pusher fans I added o the AC condenser can help cool the car a little.

 

Thats right - the fans turn on automatic with the AC on. Just use the AC to find the stock trigger wire. Got it. Splice there and then from the relay I added, add a ground to the new relay for the other side of the trigger?

I thought the fog light switch would be pretty pimp - I was planning on cutting the power wire at the switch and then splicing in the power wire from a switched accessory like the cigarette lighter instead.

Stock, the fogs lights only work when the low beam headlights are on. They will not work any other time.

 

Car overheats in traffic or hot days on its own. I can only run the AC with the car moving anyway since I have no BAC valve. The AC compressor kills the car idling in traffic in short order. I cannot run a BAC valve because it cannot compensate for the bridgeported engine. Thats another thread on how to fix that.

 

30 = Full 12v+ to power fans. Thick gauge
85= Turn on wire that you found. Also 12v+, but splice from the OEM relay
86 = Ground
87= Full 12v+ from battery (fused). Thick gauge

(someone double check me)

I would forget trying to manually switch it if your car can do it auto. Good intel about the factory fog switch though!

 

How many miles are on your stock fans?
Did you verify they are spinning properly?
Are you using an undertray? If so try removing it and see what your temps are.
Maybe you have someother issues.


John

 

I think you have 30 and 87 backwards.

30 is for fused from battery
87 would be 12V out to auxilary fans

 

Stock fans 120,000 + miles before odometer crapped out. I don't know how many miles on car. Hasn't worked in a few years.

I have an undertray and all ducting. Why remove the undertray?

This car hates me. Has for years.

 

On second thought I guess it really doesn't matter how you wire these two. Both ways should work.

Nevermind.

 

I would look in the FSM and check the fans. Maybe they are crapping out causing your issues. I don't think I have ever heard of someone having overheating problems in traffic specifically because of the front mount. Most of the time it is while driving. It is my understanding the stock fans move a LOT of air and it is hard, even in the aftermarket, to find fans that move more air.

The reason why I suggested remove the undertray is because you might not be getting enough air through the front mount, so if you removed the undertray you might be able to get more air to the radiator. I know there have been a few, although rare, instances of people who have had better luck without the undertray.


John

 

At what temps do you have the fans set to come on? Set it between 85-90 degrees and get an fc thermoswitch so the fans hit high speed sooner. Get the signal from one of the fan relays. Thats how
I do it at the shop.

 

My fans are set to come on at 80 degrees.

I found out my four blade fan is kind of lazy. It takes noticeably more effort to spin it with my finger and makes a weird faint clicking sound when I spin it.

SO - I have pulled my stock fans and will be looking for a set of those.

As far as my auxilary fans, Ive found the signal on the stock relays I'm going to use. These should help cool the condenser with the AC running.

I think its interesting someone else is mentioning an under car scoop because Ive been tossing this idea around not for the radiator but to feed my single turbo. Right now, my intake is right next to the hot fan output. Id be interested in seeing how someone else has done it.

 

If it's like the Greddy I'm thinking about, this is an FMIC that required you to mount the radiator vertically?

 

^^^ Yes, its a copy.

 

Let me give you some advice that you need to hear... ditch that intercooler. From firsthand experience that Greddy-style setup is prone to those exact types of problems you are having. And I'm talking about the real Greddy kit--the fact that you have a knockoff is not an issue. It's an inherently bad design for cooling.

Throw in the towel on that thing. It will save you frustration and possible engine damage. Go with something else. The sooner you get rid of it, the sooner you will solve your problems. Work-arounds and bandaids won't cut it--ducting, fan arrangements, etc. I've personally seen them not work.

 

^^^ I'm with you on that about now. If I hadn't butchered the front bumper I'd be more prone to listening.