I think i found the perfect way to cool my RS. What I did was, instead of grounding the relay, I bypassed it. I t-ed into the always hot, red + wire going into the fan relay (a black can looking thing closest to the firewall). I also t-ed into the black/red wire that goes from the wire to the fan. I hooked these two wires up to a toggle switch (on/off). When the switch is on, the fan is on, regardless of ignition position. So if your car is hot and you want to turn on the fan, even though the ignition is off, you can do this, which I think would be great for in between rounds at the drag strip. When the switch is off, the car operates off of the heat sensing fan switch, which for me, is a jet fan switch. So there you go, only two positions for the switch, both very usefull. A good place, I think, to run the wire through the firewall, is right next to where the steering column goes through it. Just drill a hole, there wasn't anything there for me and my car is basically stock. Make sure to use a grommet of some sort. Also make sure that you buy thick enough wire. I put the switch on that panel right under the headlight switch, it almost looks stock

good luck

 

To handle all the amps, you would have to use a really heavy gauge wire and switch. Otherwise, that is a good way to start a fire. It is much easier (and neater) to ground the relay with a single wire and small switch.

 

Definately.

To Much Amps through Too Small of a wire/switch is Definately a Bad thing.


There is nothing wrong with simply making a switch to manualy actuate the relay.

 

agreed, however, the switch is rated at 30 amps and I have a 25 amp inline fuse as well as 14 guage wire. Why not gound out the relay? That won't turn the fans on when the car is off unless you use an always hot wire for the + side of the relay, know what I'm sayin'? It's not like you need a HUGE wire for this, because your not pumpin' mega amps through the circuit. Prior to reinstalling everything I let the fan run for a long time, and things did heat up, that's why I switched to a heavier wire, which resolved things. The fuse is looking fine and the wires are doing good as well.

 

No, there is nothing wrong with your solution...however, you did not specify that you used heavy gauge wire or switch in your original post. When posting "solutions" for other people, try to include all the information, and the possible consequences if not done correctly. If someone had used whatever material at hand to create their circuit (like normal automotive 14 or 16 gauge wire), they could have ended up with a nice electric heat knife that could cut through hoses and other wire insulation.

 

um....it was my impression that the fan was there to pull air through the radiator for the purpose of cooling the water/antifreeze mix before running it through the block and it was the cooler water/antifreeze mix that cooled the block down, ot the fan blowing on it. In that case, what good will the fan do blowing hot engine bay air on a hot engine with out the engine running. If it was set to run when the engine was running then that would be fine, but not better than if the thing was just working properly. You don't want it to turn on too soon because you'll never get closed loop and the water/a-f mix won't have a chance to be cooled by the radiator. It seems to me that if you put that effort into buying what your car needed to start and stop the fan properly you'd have a better system than jury-rigging a switch with a maybe/maybe not electrical fire possibility. Add to that the off chance possibility of leavin the contraption on and returning to your car to find the battery dead. That's just my thoughts i could be wrong

 

Having the fan operate independent of the ignition switch is not a daily driver thing. It is primarily for the race track. Even though the coolant is not circulating with the engine off, you are cooling the fluid in the radiator, and forcing the hot air under the hood out of the engine compartment.

This can make a difference to some people. I prefer to use the cool down lanes, put water on the radiator with the engine running, then return to the lanes or pits and put my hood up to let the water dry. Works faster than the fan method in most cases.

 

I bypassed the relay the first time round, and very nearly had a fire. I wired it just the FAQ article says, by hooking into the switch in the block, and grounding it.

 

What size wire did you use to bypass the relay UK?

 

Bypassing the relay I don't consider an option in retrospect. It was a dumb *** move on my part.

The grounded switch I described works great, and no worries about wire heat or overload. I just used a similat gauge to the wires going into the relay. i.e. Not that heavy.

 

Not the way I'd do things...

What's wrong with grounding the relay? If you look at the factory wiring, you'll see that the fan relay(s) actually have 3 or 4 [potential] paths to ground as it is. Adding one more (a manual switch) it not a big deal and will for sure not be a fire hazard like tapping into the 12v wire is, not to mention it retains the factory control of the fan at all times even when you have it/them manually activated.

You also only have to run one wire instead of two (just one wire spliced to the ground lead of the relay to the switch, and a short wire from the other pole of the switch to a handy ground close by).

 

Ok, I am retarded, don't do this.

I wanted to do this so you could turn the fan on when the car was off, but I suppose it's just better to ground the white/green wire.

Now my fan doesn't work (not the switches or wirings fault, however).

 

TonyC,
If it works for you that's good. Just didn't work for me.

 

where the fu*k is the dam fan relay? im lookin at UK's pic....when i get to my car..... there is 3 relays.... one says MAF power in red letters..... then there is one on a flexible braket of some sort....and then there is the one on the far far far right... so it goes flex relay left, MAF power in middle, and mystery one all the way to the right... near the fender.... is the one to the right the right relay?.... if soo....what to do then....should i do this bypass thing... or just splice, hook to switch and ground......and if i wana splice hook and ground.... what do i splice it to? what color wire?..... and last question.....will it make both fans go on... or just the one?... and if just one.... please tell me where the other fan relay is.... and i will do the same for that and just hook them up to the same switch.... sorry one more, what gauge wire to use and what type of tolerences for the switch?.....thank u gents peace

 

I'm retarded, could some please post a schematic of how to ground out the relay??
thank you