I would like to install a fan switch on my 2K2. Anybody done this or know how?

Seems to me if you had the fans running before making a pass at the track the under hood temperature would be cooler making the HAI(Hot Air Intake) more effective. The fans running even though the engine is not requiring cooler water would lower the temperature in the radiator and therefore bring in cooler air to the intake. Probably only effective on cars with HAI's but who knows, might even cool the plenum having cooler air blowing on it as well.

The thermostat controls the engine temperature so this wouldn't bring the engine temperature down lower than the thermostat setting. Only the under hood air temperature.

For normal driving just turn the switch off and fans cycle under normal operation.

 

I was wondering the same thing after seeing my cousin install one on his GP GTP. I guess this is a common thing that GP owners do to their cars.

 

I say find the pos and neg wires and hook them up to a switch with a relay and make sure you put diodes in line somewhere... so power doesn't back up to any circuits.

or just turn the AC on. That turns the fans on as long as you have the AC on. And shut the AC off when you're ready to run.

 

If you chose this route, make sure you disconnect the compressor clutch wire so it doesn't engauge.

If you use your A/C and the compressor runs, the condensor gets hot. (Thats how A/C works)

You'll still blow HOT air into your engine compartment.

The best way to get your fans on all the time is to unplug your compressor and run the A/C on low. You can even just put a toggle switch in line with the compressor so you just have to throw the switch to race, then back on to ride home nice and cool.

 

Would your engine have to be running for it to work this way? I have my Camaro wired to run just the fans with the ignition switch off, fan switch on. I found the instructions how to do this on the Camaro site. Maybe it will work the same way on the Maxima. I may give it a try and see what I can figure out.

 

Here are the instructions for the LS1 fan switch mod. I'll see if any of this applies to our Maxima's.

1. Disconnect battery ground wire

2. Disconnect battery positive (hot wire) at the rear fuse box on the driver’s side engine compartment fuse panel. It has a red plastic cover on it.

3. Remove the cover off of this panel and remove the "Fan # 1" relay. It is the closest one to the engine and marked "Fan #1" on the fuse panel cover. This 3/4" X 3/4" relay is made of plastic, so be careful not to break it. Large needle nose pliers work good--but not really...I used a bent coat hanger and my fingers. Also, remember exactly which way it will go back in.

4. Pull the fuse panel out of its cradle. There will be a plastic tab on the rear of the fuse panel that will need to be pried with a flat-tipped screwdriver in order to lift the panel out of its cradle. The cradle is a 3-sided box.

5. Remove the fuse panel cover on the driver’s side instrument panel. You will see it when you open the door.

5. Remove the driver’s side kick-panel (under the steering wheel). It is attached with 2 screws and 2 small nut bolts

6. Back to the engine compartment fuse panel. The panel has been lifted out of its cradle. You will note that there is a small dark green wire running into the bottom of the panel where the relay has been removed. Strip a length of 14 gauge wire (at least 8' long) and insert it into the bottom of panel, so as to make contact with the green wire's terminal and the fan relay when its pushed back in. Push the relay back in insuring that the 14-gauge wire now makes contact with that circuit.

7. Slide a section of rubber tubing over this wire. This will hide the wire, and make the installation look "factory".

8. Snap fuse panel back into its cradle.

9. Route the tubing with wire in it along the large Air Pump Supply tubing, which runs back along the driver’s side fender well. Attach this tubing together with plastic wire ties. Cut and terminate the use of the tubing that you added, at a point that the wire will go under the hood bracket, below the windshield, and through the door opening at the door hinges. It is impossible to run this wire through the firewall. Then run the wire under the doors most forward rubber molding. Exit the wire where the plastic trim pieces come together next the instrument panel fuse box. Run the wire through the side of the fuse box and terminate in the area of the lower kick panel.

10. Run a short piece of 14-gauge wire to a GROUND. I used one of the bolts that mount the grayish piece of plastic to the black metal supports. There is one on each side of where the kick panel would go.

11. Run these 2 wires into a non-grounded on-off switch of at least 15 amps rating. I got mine from Radio Shack. I also crimped 2 female spade connectors on to these wires. Then they just slipped onto the switch.

12. Drill a hole in the plastic kick panel to mount the switch. You will note that this panel is VERY thick plastic and will need to be ground down on its back side in order to put the switch collar through it. If you can find a better location for the switch--Good Luck! ---- You can sandwich the switch between the stable part of your steering column and the plastic panel. This secures it enough for me to turn it on and off several times a day.

13. Replace the kick-panel, and hook up all battery connections.

Note #1: This mod will run both fans at slow speed. It will not set any computer codes, nor will it effect the normal automatic operation of the fans.

Note #2: Since the battery will be disconnected, the radio security code will need to be re-entered in order for the radio to operate. Check your owner’s manual, and know your code BEFORE removing battery power. ----- This did not happen on my 98.

Good Luck, this seems a little involved, but this is really a fairly simple mod--Take your time!!!!



Addendum to the regular Fan Mod


It should also be known that when these fans activate in series and they work at a higher speed. This will happen normally when your temp reaches 238 degrees. To wire your fans to activate at this high speed, first do the mod above. After completion, take a small piece of "jumper wire" connecting the small green wire of relay #1 and the small blue wire of relay #2 (gray relay right beside #1-it is labeled on the cover). Any wire at least the size of these wires and about 3-4" long will work. Simply shove each end of the jumper wire into the bottom of the wire connections. This will energize the second relay and activate the fans in series, or high speed. This is great for the summer months around town or at the track. It will, however, set a non-performance related SES light that will go away over night.



I wired my high-speed mod to a switch and mounted (tie wraps) it to the large gauge power wire that connects to the fuse panel. I used a Single Pole-Single throw switch just like the one above except the terminals were enclosed and it already included two 6" leads. I went back and removed the #1 and #2 relays and places one lead on the green #1 relay wire and one of the blue #2 relay wire so that with the relays plugged in, the wires make good contact. With this switch 'ON' the jumper wire is active, so the fans are working at high speed. With the switch in the off position, the fans work in the normal low speed and set no codes.

 

I don't see how this will accomplish what you want it to. Maybe I'm wrong, but here goes.

Running the fans when the engine is not running will blow the hot air coming from the hot radiator into your engine compartment. If your hood is closed, there is no efficient way for the hot air to escape the engine compartment. If your hood is open, then your engine compartment is going to be cooler than the hot air being blown from your fans.

As far as cooling off the coolant, not going to happen. It will cool off the coolant that is in the the heat exchanger part of the radiator, but that's not much. Without the water pump running, no coolant will be cycled through the system, so the rest of it stays hot. Reminds me of the water to air intercooler on my Syclone. Putting ice on the water reservoir (before I knew how to manually cycle my pump) did very little to cool the water. When I had the pump running, the water was ice cold and my 1/4 mile times dropped dramatically (I could up the boost).

As far as cooling a hot plenum...yeah right! That thing gets soooo hot, it would take a glacier to cool it down. I managed to keep it cool by constantly using ice on a 60 degree day.

 

You are right, if the water pump is not turning, the coolant from the engine is not going to be cooled. Maybe I'm wrong too but seems to me if the coolant is cooler when it goes into the engine which it will be if the fans run constantly rather then cycling as they do, then it won't take as much coolant to cool the engine thereby returning less hot coolant into the radiator. With less coolant going into the radiator it will be cooler and emit cooler air from the fans. My thinking is, the more air you bring across the radiator the cooler the radiator will be due to less coolant being circulated. As far as cooling the plenum, I'm sure it wouldn't have much effect but every degree can count. Just like every pound removed on the car counts. If your under hood air is 130 degrees verses 140 degrees then maybe the intake will be 10 degrees cooler as well.

Of course the best way to solve the problem is with a true CAI. Our under hood temperature would certainly not be as critical. Unfortunately nobody makes a good one. I want one that pulls air from the same location as the factory intake but double the flow area and feeding into a large cone filter or a filter the area of my Camaro's. I definitely don't want one that sticks in the wheel well and get mud and water on it from the tire.

 

There's a write-up with pics in the 4th Gen FAQ

 

This is what I was looking for. Hopefully it will work for my 2K2.

Here is the info for others:

This switch allows just that, manual control while the car is off in one position and normal operation in the other position.
You have to a DPDT (double pole, double throw) switch. DO NOT get one with center off.

The relay is located just in front of the battery. You will see them labelled Cooling Fan Relay 1, 2 & 3. We are only going to connect into Cooling Fan Relay 1, it is located in the lower right corner.

Remove the two screws holding the relay, remove the top cover and then the bottom cover so you have access to the wires beneath the relays. Turn it over and look for the wires under Cooling Fan Relay 1. You will see two small gauge wires (these are the control for the relay) and two larger wires. (these are connected directly to the fan motors)

The only two wires we are interested in are the G/Y (Green with yellow stripe) and the LG/R (Light green with red stripe). Cut both of these wire leaving enough wire on each end to strip and connect into. (Indicated by the white X on the picture)

Connect four lengths of wire (for each of the cut ends) approximately 6' in length (to reach inside the car). I soldered mine but you can just strip and wrap the wires together or use a connector. Make sure you label them so you can tell them apart when they are inside the cockpit. I used 18 gauge wire, this is only signal wire for the relay it does not power the fans. Probably could be even smaller but I like to err on the side of caution.

I used red wire for the G/Y connections and green wire for the LG/R connections. I put black tape around the two wires that came from the relay for identification (they connect to the center terminals of the switch). I used the grommet just above the fuel filter to get into the car.
Once inside the car just hook them up to the switch as shown in the picture.

The other two connections on the switch go to a +12 hot wire and the other to ground. I used the +12 wire going to the hazard switch and tapped into it.

I have my switch so that down is normal operation and up turns on the fans manually.

It sounds a lot more difficult than it is, the whole operation should take a maximum of one hour most of which is deciding where to come through the firewall and where to mount the switch.

It could also be wired for high speed operation but I decided that the normal speed was sufficient for my needs.



Original thread.