LS1 Fan Installation

[agreif]

Full Size Pictures: LS1 Fan Installation

LS1 Fan Install
Thought since I always ask so many questions that I would throw together a little how-to to clear up any questions that may arise when doing this mod. it's actually pretty simple. Took me the better half of a day to get it all done to the way I like it clean and organized. Click on any of the pictures for larger ones.
Hardware/Tools Needed
1. Drill
2. Rubber Mallet/Hammer
3. Sockets
4. Large wrench to take off 1 7/8" nut
5. Pliers
6. Wire strippers
7. Flathead screwdriver
8. Electrical tape and soldering iron (if you want to solder any of the joints)
9. Flex-a-lite VSC Kit
10. 3/4" wide by 1/8" thick steel
11. 3 - 1/4" x 1" long bolts
12. 7 - 1/4 flat washers
13. 3 - lock washers
14. 3 - 1/4" nuts
15. 1 - 1/4" x 3/4" long machine screw

OK here we go, nothing done yet


Step 1
First thing that you want to do is take off the cover that they have on there, just pry up those tabs and the larger body will pull out of the holes. Put those to the side until the end


Step 2
Next take off the intake tube. This will let you get the fan shroud off. The intake side gave me a little struggle, had to pry the tube out of the "gasket" that the slides around the tube. Once I did that the gasket came off the intake and I put it back on the intake tube.


Step 3
Here is where we are with the intake tube off.

Step 4
Now unbolt the upper fan shroud, there are two bolts on top, that's it, nothing else


Step 5
After the shroud is unbolted, separate the top and bottom half fan shroud by undoing the clips halfway down. These are similar to the ones on the cover from the beginning


Step 6
Once that is done you can pull the shroud out of the supports on the core.


Step 7
Pull the coolant tube towards the engine and pull the upper half of the shroud out.


Now you just have the fan staring at you.


Step 8
To get the fan off you need to loosed that fan nut. Beforehand, hit the fan nut with a little penetrating oil (I just used WD-40).


On my NBS 01 truck the nut is a regular thread, so get a wrench on there (I believe it is a 1 7/8" nut - I only had a pipe wrench that would get that big) and knock it multiple times with a rubber mallet counterclockwise until it comes loose. If you try to just loosen it by hand the pulley will slip on you, while the belt is stationary.


Here's what you have left over once you get the fan off. Notice that on the NBS trucks you don't have those bolts holding the pulley on like you did on the OBS trucks (where those 4 holes are).


Step 9
The next step it to test fit the fans.


Step 10
The mounting holes from the fan shroud should be able to be used on the new fans. You will have to cut a little of the trim off to make room for the bracket supports.


Step 11
Now that you have an idea where things will mount up, go ahead and mount the VSC. You may not need to predrill holes but the screws that came with the kit had a blunt end so I had to in order to get them to thread.


Step 12
Now that you have that mounted the VSC, fit up the fans again and see where the brackets can be mounted. Mark where you would want the hole in the shroud and measure how far it is from the stock mounting hole to where you want to mount the bracket on the fan.

Keywords: LS1 Fans Install Installation Remove Clutch Fan

[agreif]

Step 13
Take your steel piece and mark the holes and drill 1/4" holes. Then cut it to length. Do that for the other top bracket and then the bottom bracket. What I then did was attach the top brackets to the factory holes and fit up the fans again. Then I lined up the bracket where I thought it should go and drilled through the fan shroud to make sure the holes would line up correctly. Once you get the top holes where you want them, tighten all the brackets (top and bottom) to the shroud and test fit to make sure your holes line up where you need them to. Tighten up the top brackets and then use your machine screw to secure the bottom.


Step 14
When you get the VSC it has great direction that come with it as well as additional ones on their site.
Variable Speed Control Instructions *Note you should not have to drain the coolant for this install. After you have wired the two fans in parallel (pos to pos and neg to neg from the two fan motors) just follow the directions on wiring.
You have to hook into an always hot (battery) wire, and ignition wire, a ground, and the AC activation wire (so that the fans come on with the AC). To do this I wanted to get to the Underhood Body Electrical Center (UBEC). To do that you need to take off the cross support first. Then the plastic cover can come off.


I tapped into the battery wire as shown here (red wire).


I then tapped into the ground here. It's a little hard to see, on the fender wall, almost behind all the fuses. There is a small yellow connector with a black wire attached.


Step 15
Then a wire that is hot with the ignition on needs to be found. I looked in a Haynes and found a pink wire to work. There are a plethora of em, including ones that go to the injectors, sensors etc. I tried to pick one that went to the headlight harness so if anything went bad at that connection there was less of a chance of messing anything mechanical up.


Step 16
The next one to tap into is the AC wire. Again, haynes showed it as dark green for my truck. The only way to test this is to have the truck running, check the wire with the AC off and then with it on and the AC clutch engaged. You should get a + voltage when engaged and nothing when it's off. If you try and check with the engine off you won't get anything. Wire color may vary if you have an OBS truck or 02+. Test it for yourself to be safe.


Here's where I spliced into the ignition and AC wires


Step 17
Next you connect the temperature probe. Push the probe through the fins right at or just below the coolant intake centerline. Make sure it is in there; you don't want too much sticking out the backside as the sensor is closer to the back. Cap the frontside of the sensor to prevent it from backing out.


That's it, test the fans out. Here's the new look without any harnesses.


Clean it up with some wire looms and it looks basically stock.

Enjoy! If you have any questions feel free to ask. You can find me on PA as New95 and on LS1Tech as agreif.
Here is a link to another quick little tech article on an Eaton install and a 4.8 to 6.0 swap.

Eaton Install
4.8L to 6.0L Swap

[LARRY01Z28]

Great write up man.

[ff_jeff]

Why did the pics dissapear? He delete them from the photohoster?

[ff_jeff]

LS1 Fan Install I found this on google. Its A walk through.

[ESchey]

Good work!!