I have the dual fans setup in my 91 z but I no longer have my A/C hooked up so that makes the passenger fan useless to the computer right? The drivers side fan would be the only one to work. If so then would my car cool a lot better if I switched out the dual fans and put a larger single electric fan in instead?

 

You can still stage a progressive fan system.. That's what I did on my last car (88 bird with carb).. I used two fan switches (FS1 and FS5 in GP Sorensen if I remember correctly) and hooked them up with a pair of relays (one for each fan) along with fan-on indicator lights and manual override switches (the fans would come on and shut off by themselves, but if I turned the a/c on, I would manually override them and turn them on full-time).. Pretty awesome setup really... I used the dual-fan relay wiring from a fwd buick that I found at the junk yard (both relays were on the inner fender, and the wiring was fairly compact and independant from the main harness)...

To answer your question though, yes you would get better cooling from the one large fan rather than the single smaller fan..

Another option might be to get the fan switch (which controls the secondary fan on your car) from a L03 car (which has a single fan)... This way, your second fan would come on at 220 also... I'd have to look up the specs to make sure, but I think the standard aux fan switch on a dual-fan equipped car turns on the secondary fan at something crazy like 245*...

 

I deleted my A/C as well. Being cheap I wired the A/C fan relay back to the engine temp fan relay. Currently they both come on at the same time so cool really well. A better way would be to include a manual override into the A/C fan so you can force it on. That way if you see things getting warm you can turn one on ahead of time. I like it for waiting in line at autocrosses.

 

I guess I should have added this in my first post but I DO NOT want to add all this extra wiring and relays and crap to my car. The last thing I need is more cluter and wires to fish through the car. I want a simple SAFE setup. The thought of rigging 2 fans together makes me nervous. I understand the relay helps and is needed but I just dont want to start cutting and splicing and adding more wires to my car.

I want the chip to control the fans. period. I didnt want to get that in dept to this question. I just wanted to know which setup would be better for cooling.

Since I do not have my A/C hooked up then that means the second fan will never turn on unless the temp get to 245?........actually I just thought of something. I think I better keep the dual fans in my car becuz if one motor goes bad then I have the other fan to keep the engine cool. I can just swap the plugs on them. Let me think about this setup here. thanks for the input guys

 

You already have two fans and two relays so not really adding any "clutter". They are already wired together in the harness and being fed by one large orange wire. The only difference between the two fans now is one relay turns on with a temp switch and one turns on with a computer switch. Your question asked about the best way to cool and I have found that the best way is to use what the general gave you. Your computer will not turn the fan on with the AC deleted unless you jumper the AC sensor together. That requires a wire or switch unless you want to open the hood and do it each time you start the car.

 

Fred, give me some details on this A/C sensor. where is it located? Your saying I can just stick a wire in the terminals and wrap it up and the comtputer will turn the fans on at the programmed temp?

 

No, jumping the wire together tricks the computer into thinking that the A/C is on so the fan will be on all the time. I ran mine that way for a while but it was annoying and the car ran too cold. It is two small wires (mine were white) attached to a red connector that plug into the AC line that runs down the passenger side frame rail. It is the only connector into an AC line. Pull it off an put a paper clip between the two points and the 2nd fan will come on when the car is running. If you want it to come on with the other one, find the wire out of the engine temp switch (between plugs 6 & 8). Trace that back to the 1st fan relay. Note what position it is in the relay. Now find the 2nd fan relay and get the wire from the same position of relay 1 and join it to the wire from the temp switch. Then they will both come on with the temp switch.

 

now that sounds all fine and dandy but again I really dont want to be "modifiying" relays and wires like that. I already had a 91z burn to the ground because of faulty wires so I dont it happening again. If I did it that way then would the 2 small fans cool faster then just one big elcetric fan? i would rather just swap in the big fan and call it a day. I'll sleep better at night knowing that I didnt mess with relays and wires and crap. But again, I want to know if the fan will cool better.

 

All you need to do is wire the two fans on the same circuit so they come on with the fan temp sensor.

I think the way GM setup the dual fans was kinda dumb anyway. What good is passing air through only one half the radiator when the ac is off.

 

but see, i dont feel comforatable wiring two fans to one circuit. those motors generate a lot of power and they may burn the realy out and cause a fire from overheating the wires.

 

Maybe someone just didn't pay attention, but why not replace the fan switch in the passenger side cylinder head with one that will engage at 220*?? (so that way you use it the way GM designed it, just a cooler temp (better than 245*))

Then there's no alteration of anything, you're using the factory designed wiring, and everything.. Just get a fan switch from a single electric fan equipped car...

 

There are fuses and relays in the car so that you don't have a fire. The fuse should blow if there's a problem.