How to Replace the Mechanical Engine Fan with an Electric Fan
1990-1994 Lexus LS400
I decided to swap out my mechanical fan for an electric fan for several reasons. First off, it is a very cheap and easy mod to do. Second, it will free up some horsepower. Third, it will cool the engine better. And lastly it will finally give me some room under the hood (never fear of dropping a socket again!!). The fan I bought is the Zirgo HP reversible 16” fan. This fan should only run you about $65 and if your not running FI then you only need one to start cooling better. However, 16” is too big, but with proper modification it will fit PERFECTLY.
- Socket kit
- Thick screwdriver
- Cutting utility
- Electric fan...obviously
- Zip ties
- Crimping wire connector
1) Unbolt the fan shroud and then take sheet metal cutters and cut apart the shroud so you can fit the pieces out around that massive fan and radiator hose.
2) Take off the fan. This is the easiest part and only requires for you to take off 4 nuts.
3) Take off the fan clutch assembly. You need to loosen and remove the 4 nuts in order to take off the fan clutch assembly. This is the HARDEST part by far because the nuts are on very tight and you can’t get any leverage. To help you out use that handy WD-40 and liberally spray it all over those bolts. GOOD LUCK!! LexLS.com tip: Use two wrenches to remove the fan clutch. Put one wrench on a nut to use it for leverage. Use the other wrench on another nut to remove it. Mess around with it and you'll figure it out.
4) Now that you have taken off that fan clutch assembly you need to put those 4 nuts back on, but if you have looked closely you would have noticed the threads don’t go that far. That’s right folks, you need some washers. I used two on each bolt.
5) Cut the fan down to size. If you have already tried to see how it would fit you would have found out that it does not fit unless you cut off two sides.
6) The next step is to mount your fan. I haven’t figured out how I want to mount it, so I temporarily mounted it with some zip ties and utilizing one of the fan shroud screws.
7) Now for the electrical work. Finding a ground point is easy, simply connect the negative lead to any metal part of the chassis. Now open up your fuse box, and then take off the two bolts holding on the fuse board. Some people like the peace of mind of having a relay to protect your fan, however I’m not one of those people. It is a good idea to put a relay on, I just didn’t. You want to tap power from your ignition, or the fans will be on all the time, and obviously you don’t want that. The wire you want to tap is white with two red stripes. Tap into that wire, close up the fuse box, and put in your keys to the accessory position or just start the car and they should work.
You will notice the fan is very loud and even with the hood closed you can hear if it is working. You should also notice that your engine runs a slight bit cooler. Another plus you should notice is the amount of room you have now gained. It frees up some horsepower (although not humanly noticeable Lextreme tells me). Congratulations, if you did everything right and it runs properly, you have just completely one more mod to your Lexus BEAST! Enjoy!
LexLS.com Notes: Thanks for contributing the article Nick!
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