RevLimitLaunch

so i was thinking today about the whole fan mod ordeal. is it possible to just wire the fan motor straight to the battery with a switch mounted inside in between the connection? haven't heard of anyone doing it so figured i would give it a shot.

bryant

yes thats how i have my fan ran.
just remember to turn it on.

rynberg

Doing so would bypass the relays....a very poor idea. You would have to always remember to turn the fans on!

If you don't have the PFC, just get an FC thermoswitch and be done with it. Or if you want to get fancy, Dale Clark recommends the HKS fan controller.

bryant

you still have a relay?? what relays do you mean?

SINxSELEKTAH

iTrader: (2)

i kinda want to undo the fan mod, but wires give me a head-ache

scotty305

iTrader: (2)

I think you need to clearly define your goals, and THEN start looking into how to accomplish them.

What is your car doing, and what do you want it to do? How do the cooling fans factor into all of this?

-s-

Sgtblue

iTrader: (16)

The stock relays are the four small "boxes" on the passenger side of the engine bay, near the intake box.
What ordeal? IMO, easier than what your proposing...and MUCH safer.
http://www.fd3s.net/fan_mod.html
http://rx7.voodoobox.net/howto/fanswitch/fanswitch.html

Mahjik

iTrader: (1)

If you bypass the relays, you need to make sure to run the proper wire size to handle the amps of the fans.

CantGoStraight

How can one wire and one switch give you a headache ? I can only imagine what a pain in the *** this car must be for you. ! ! ! LOL

OcTane

^+1

RevLimitLaunch

i planned on taking the power wire off the fan motor and hooking it up straight to the battery with a switch in between. no headaches, would take about 30 seconds, plus time mounting the switch. remembering to turn it on is no problem at all. other than that would there be any problems, im guessing no, but i like to make sure. thanks

Sgtblue

iTrader: (16)

Not ONE reply suggested that there wouldn't be any problems. Even Bryant (who didn't even know where the factory relays were) cautioned you about turning them on. You claim that remembering to turn them on won't be a problem. Are you 100%, absolutely sure? Because there isn't anything on the car MORE critical than cooling. All you have to do is forget ONCE, and your buying a motor. You referred to it as an "ordeal". You never indicated a reason for messing with the factory system anyway. If your motivated to improve cooling, there's the fan mod which I linked to, or the FC thermoswitch that rynberg suggested. Either one or both are worthwhile, time tested, safe IMPROVEMENTS on the cooling system. Instead, you want to run 12v high amp. power through the engine bay, into the passenger compartment and through a switch (I'm guessing one of those really neat aircraft toggle switches from ebay) and to your fans. No mention of adding a relay or even a fuse. To me, that's senseless and dangerous. If a car fire, or baking your engine because your girlfriend's hand is in your lap and you forgot to flip that switch doesn't qualify as "headache" what does?

rynberg

Just in case you haven't figured it out....THIS IS A BAD IDEA! What is wrong with your cooling system now that you are trying to "fix"?

mad_7tist

yea/\

and if running a single ground path to a cabin switch seems like to much work, or is complicated, you need to step away from the tools and close your hood.

RevLimitLaunch

nothing wrong, just thought it'd be easier to wire it up since it would take seconds to do, and no i do know that an inline fuse is to be used. im not an amateur at it haha. i know i won't forget, it's not the first car i've had one in, there have been several and i always check my gauges every minute or so, never know when somethings going wrong with your car randomly. i wasn't asking to get b*tch*d out on all of this, just simply if it could be done, wasn't sure becuase i didn't find any threads where someone has done it.

scotty305

iTrader: (2)

Wait a minute here. You're already talking about your PLAN OF ACTION, before defining your GOAL. There is a HUGE difference, and I think you're missing the point that everyone's trying to make. Let me say this as clearly as possible:


YOUR PLAN OF ACTION IS UNSAFE,
There are a few good reasons that nobody just runs a wire with a switch to the fans. The fans draw 15-30 amps of current when they're operating normally. You would need 8 gauge wire to be safe at 30A, and you'd need to find a switch that can handle 30A. That's not the sort of thing you'll be able to buy at RadioShack. If the fan blades ever get stuck, it will draw even more current, so you'd better have a 30-40A fuse in there as well, to prevent the wires from catching fire.



But all this 'electrical safety' talk can be a real drag. I don't like saying "be careful or you'll burn yourself, son!" It makes me feel feel like a grumpy old fart.



Let's step back and think about what your GOAL again. You've probably already thought of a GOAL, in your head, but you didn't say it on these forums. I'm going to assume your GOAL is to keep your car at a certain engine temperature. Let's say 190F-200F, that's nice and safe. Let's add another GOAL; we want to add as few wires as possible, and we want to modify as few existing wires as possible.


So far, your PLAN is to add a switch, and watch your gauges, and be sure to flip that switch every time the temperature gets too hot. If you're really careful, you'll always flip that switch at the exact same temperature, let's say 190F. The down side is that if you forget to flip this switch, the engine will get too hot. Or if your gauge is malfunctioning, you won't see the temp and you won't know when to flip the switch. So far, that's two possible ways for things to go wrong. If the switch doesn't work, that's a third possible thing to go wrong.


Here's another PLAN you might try, it's been used by racers for a long time. You need to buy a thermoswitch (also called thermal switch, or non-linear thermistor). It's just like a temperature sender for a gauge, but instead of sending a temperature signal, it just switches ON or OFF when the temperature reaches a certain point. The OEM fan control system has one, but it's switching at a high temperature (226F). The thermoswitch from the 1986-1991 RX-7 switches at a lower temp (203F), and you don't need to change any wires on your car.
Check it out here: https://www.rx7club.com/3rd-gen-archives-73/fc-thermoswitch-fd-447606/



Hope this helps,
-s-

Sgtblue

iTrader: (16)

Then why do anything?
Again, if nothing is wrong with the system, nothing can be easier than to LEAVE IT ALONE. This brings me back to my earlier guess that you just want to install some silly looking switch in your car.

You asked and were essentially told that it would be stupid. Then you reply indiating that your ignoring the advice and intended to do it anyway. Why did you ask in the first place? Better yet, ask yourself why you didn't find any previous threads on it.

adam c

iTrader: (2)

How about if someone else has to drive the car? Can you trust them to always flip the switch at the right time. What about smog checks? The mechanic will have your car? Will he flip the switch at the right time? If you leave the switch on, the engine temp will be low for the check, and you will fail.

Revlimitlaunch: There are lots of smart people that have posted on this thread. So far, you have not shown that you belong in this group

donz

iTrader: (2)

I think most people on here are saying it can be done. but why do you want to do it? No offense really, I'm a noob so I've just wondering about the advantages.. Do you considering wiring a switch in to the thermostat so that you can turn it on manually, and have the thermostat kick in when it's off and that the right temp?
People have to calm down, if he get's the right wires relays/fuses, and always turns it on, what's the prob? there are high power wires inside cars, what are people getiing so worried about?

RevLimitLaunch

ok idea gone, i already have a 180 degree thermoswitch lol. i just never heard anyone on here do a direct switch fan mod, so thought i'd ask if it could be done without a big hassle of eliminating the relays and what not. so thank you for who answered my question, i didn't need to be b*tch*d out on why i should or shouldn't do it. i just wanted to know if it could be done. i plan on doing the actual fan mod come spring time when autocrossing starts up around here again. as of now its very very cold and there's snow on the ground :smiley_12.

scotty305

iTrader: (2)

^^ Thermoswitch or ThermoSTAT? Where did you install your 180 degree 'thermoswitch'? How many wires are connected to it?


This is a thermoswitch:



This is a thermostat:





PS, don't assume that people 'bitched you out' or that anyone on here doesn't like you. This is just the internet, don't take it personal just because we didn't use smilies when we told you that your plan was not the best way to do things.


Say for instance you installed a 35A fuse, a 40A switch, using 8 gauge wire, and everything was safe and worked fine because you know what you're doing. I don't want some rookie to read your thread and then try to do the same thing with a RadioShack 10A switch, some 16 gauge speaker wire, and no fuse.



"I explain things because I care,"
-s-

RevLimitLaunch

its cool, i still got love, and i got the thermoswitch don't worry, i also have a failsafe 180 degree thermostat in there too for safe measures!

rynberg

Where did you get this "180-deg thermoswitch".....even the FC switch doesn't turn on until 203F? Turning on the fans at only 180-deg is pointless and doesn't let the car get warm enough for maximum performance.

We now have a 2-page thread in which you still haven't stated why you are messing around so much with the cooling system. If you don't have the PFC, just install the FC thermoswitch and be done with it. Or even do the "normal" fan-mod if you want.

RevLimitLaunch

well i already stated ill be doing autocross....and the direct switch for the fan was already told why i brought it up.

LovMyRx7

iTrader: (7)

You know what is everybody complaining about? I just did the fan mod switch from here http://rx7.voodoobox.net/howto/fanswitch/fanswitch.html. Just follow the instructions exactly. And my fans still turn on if i forget to flip the switch. So i don't know what the big ordeal is?