JennaBear
Resident Ninja
Here are pics of mine:
Efans Installed
- Thread starter Max
- Start date
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ELOOSECANNON
TYF Newbie
Looks great, it really freed up alot of room in the engine bay didn't it.
OKLAGMCRUISER
Need drop...send $
looking good, jenna, but your engine bay is very dirty...very dissapointed in you for that...lol.
Grocery Getter
A guy with a truck.
Hey, I've been emailing Justin about this. A write up would be swell, specifically the wiring part when using a 2 pin OEM harness. I mean the fan part is pretty straight forward to me it's the electrical that I am clueless about. Everyone says using the OEM 05+ fans and harness is "plug and play" but it seems a smidge more complicated and maybe it's not if you know where to plug what........ I'm gonna do the e-fan next week so if you happen to get the write up in before then that would be nifty...........
blueflamed03
Elite Member
sounds like a nice mod.........hhhmmmm
AtomicHoe094
Atomichoe094
not sure if you guys are banned or not, but heres JKs write up someone was talking about.
http://www.tahoeforum.com/showthread.php?t=1718&highlight=electric+fan
http://www.tahoeforum.com/showthread.php?t=1718&highlight=electric+fan
I did this back in 04 before the silverados came stock with e-fans. Back then everyone used vette/camaro fans. They are smaller than the new fans but do just as good and can be had for 60-70 dollars. I also installed a 160 thermostat so water temp gauge never goes up past the 185 mark no matter how hot it is outside or how sprited my driving is 
OKLAGMCRUISER
Need drop...send $
http://bertok.us/agreif/fans/fanstech.htm
here is the tech/how to i used to install efans in my 99 sierra. The author did a great job!
here is the tech/how to i used to install efans in my 99 sierra. The author did a great job!
Here is JK's writeup:
I have been asked by a few people for a parts list and instructions. I opted to put together my own kit, purchasing universal items here and there. Most of the wiring, relays, etc were stuff I have laying around the shop. It may be easier to purchase a complete kit from sources such as Summit Racing and Jegs, for they have everything you need with much more detailed instructions than I would be able to provide. I have, however, provided a list of parts I used and the removal procedure for the factory fan, shroud, fan clutch,etc.
For installation of your new electric fans, follow the guidelines with your new assembly. If your kit does not come with instructions, such as with some universal kits, feel free to PM me with the type of kit you purchased and I will help as much as I can. As for wiring, some kits will come with the required wiring, relays, instructions, etc., but like above, you may PM with any questions. It's been raining like crazy here and I've been so busy with work that I haven't been able to take any decent pictures, but will when I get a chance.
Here's a list of what I used:
Two(2) 16" Proform electric fans, S-curve type blades(quieter than straight blade design), 2500cfm each, w/mounting kit.
Three(3) SPDT relays, 30/40A. One for each fan, one to operate fans when a/c clutch is engaged.
One(1) adjustable electric fan control thermostat
One(1) 3A diode, to prevent feedback current to a/c clutch circuit
Two(2) ATC type fuseholders with 30A fuses
Misc related 12 ga. wire, solder, heatshrink,etc.
Following is the procedure for removing the fan shroud and fan blade/clutch assembly. This is for the 4.8 and 5.3L engines. The 6.0L procedure is almost identical, with the only difference being in the lower fan shroud removal. When I get a chance, I will post some detailed pics for the procedures below, pointing out locations and such.
Special Tools Required
J 41240 Fan Clutch Remover and Installer
J 41240-5A Fan Clutch Wrench
Fan Shroud Removal-Upper
Loosen the air cleaner outlet duct clamps at the following locations:
Throttle body
MAF/IAT sensor
Remove the radiator inlet hose clip from the outlet duct.
Remove the air cleaner outlet duct.
Reposition the inlet hose clamp at the radiator.
Remove the inlet hose rosebud clips from the following locations:
Fan shroud
Air cleaner outlet duct
Remove the inlet hose from the radiator.
Reposition the radiator inlet hose.
Remove the fan shroud retainers.
Remove the fan shroud bolts
Remove the upper fan shroud.
Removal Procedure for fan blade/clutch assembly
Install the J 41240 to the fan clutch. Using the J 41240-5A Fan Clutch Wrench on the hex shaft of the fan, loosen the fan clutch assembly.
Remove the fan blade.
After removing the fan, you can remove the lower fan shroud assembly.
The 6.0L will have a couple oil cooler lines attached to it which will need to be removed.
Hope this is helpful.
Flex-a-Lite fans from Summit Racing
Perma cool fans from Jegs http://www.jegs.com/p/Perma-Cool/Perma-Cool-Cool-Pack-Electric-Fan-Units/749975/12051/-1
Proform GM electric fans http://performanceparts.com/product_group.php?vendor=PRF&pgid=11&sgid=70&orderBy=MembersPOPRank%20ASC&page=1
AtomicHoe094
Atomichoe094
im not to sure that was necessary mr45...
Grocery Getter
A guy with a truck.
Again, the write ups are all the same and don't address my issue. I am going to use the BB 2 pin harness and I don't know where the PINS go. I am going to assume the rest is straight forward power/ground. I have not seem the harness yet so I can't say what I need to know definitively but I am certain I don't know where the PINS go......anyone have a pic of that?
JennaBear
Resident Ninja
The PINs are on the PCM, you just plug them into the proper places.
Grocery Getter
A guy with a truck.
The PCM as in what Justin swaps out for a tune? Is there just an empty slot somewhere?
Alrighty then.
Figured I'll post it for the banned members, or in case TF ceases to exist.
Grocery Getter
A guy with a truck.
I found a good wiring write up at Nelson Performance... I get it now:
Electric Fan Wiring Harness Installation
NOTE:
If you would like to download these instructions in a printable PDF file click here.
Installation:
Contents:
Wiring fan harness
Mounting screws
Red 18g line taps
Flex fan harness includes also:
4 – Butt connectors
Heat shrink
Tools needed:
17mm wrench
¼ nut driver
10mm wrench
7mm socket/ratchet
Pliers
Pic or thin screwdriver
Wire cutters
Flex fan harness requires also:
Butt connector crimper
Using a 17mm wrench remove the nut from the red battery junction box located on the driver’s side engine. (fig1)
Locate the ring terminals that fit the junction box. These wires will be the two red and one white wires. In order to close the red box, you may have to notch out the bottom of it using wire cutters or a hand held razor/box cutter. Secure the 17mm nut onto the stud and close the lid.(fig2)
Located just to the left are the two 10mm bolts that hold the junction box to the alternator bracket. Remove one of the 10mm bolts and locate the ¼ ring terminals on the harness. Ground the wires using the 10mm bolt.
Located between the junction box and ground mounting point is a group of wires covered by loom. Open up the loom and locate the green wire. (The wire may be light green or have a white stripe as well. If one fan does not come on high speed the incorrect wire was tapped. To test the wire, a volt meter may be used to test for the presence of 12 volts when the truck is running and the AC clutch is engaged.)Using pliers, crimp the provided red tap to the green wire. Locate the green wire on the fan harness and attach it to the red tap. (fig3)
Remove the black cover from the PCM. This is done by pulling outward on the cover and clearing the two plastic tabs. Using a 7mm socket remove the blue PCM connector. This is the connector closest to the engine. Remove the grey retaining cover from the topside of the blue PCM connector. (If you have trouble removing the grey cover, simply use some pliers. A small flathead screwdriver can be used to pry the grey retaining tabs out.)Turn the connector over and using a thin pick or screwdriver, press on the white retaining tabs on each side of the blue-clear cover and remove it. Lubricate the blue PCM wire on the harness. Simply push it through pin 42 until it secures itself. Pull on the blue wire to ensure it is secure. Reinstall the blue-clear cover and grey retaining cover on the PCM connector. Reinstall the PCM connector.
Locate the LS1 fan connectors on the fan harness, install them and connect to the fans. Be sure to secure the wires with tie straps.
Using the supplied screws, attach the relay connectors to the upper left corner of the PCM cover. Be sure to clear the PCM when installing the screws.(fig4)
Flex-Fan or Universal Fans:
The fan harness will have four power wires coming from the relays. They are grouped in a wire loom and are attached to your existing fan motor wires using the supplied butt connectors and heat shrink. Be sure to cut the heat shrink to the appropriate size and install it over the wire before crimping the butt connector.
*Notice
The four wires are grouped in pairs. Each pair belongs to one fan. Do not tie the pairs together or swap wires.
Verify harness is installed correctly:
Start the truck and turn the AC on. As soon as the AC clutch engages, one fan will turn on high. When the engine coolant reaches the desired turn on value in the PCM, the other fan will turn on high. If the AC is off and the coolant reaches the turn on value, both fans will turn on low.
The relays don't plug into anything they just need to hang out, the PCM is in the fuse box
Electric Fan Wiring Harness Installation
NOTE:
If you would like to download these instructions in a printable PDF file click here.
Installation:
Contents:
Wiring fan harness
Mounting screws
Red 18g line taps
Flex fan harness includes also:
4 – Butt connectors
Heat shrink
Tools needed:
17mm wrench
¼ nut driver
10mm wrench
7mm socket/ratchet
Pliers
Pic or thin screwdriver
Wire cutters
Flex fan harness requires also:
Butt connector crimper
Using a 17mm wrench remove the nut from the red battery junction box located on the driver’s side engine. (fig1)
Locate the ring terminals that fit the junction box. These wires will be the two red and one white wires. In order to close the red box, you may have to notch out the bottom of it using wire cutters or a hand held razor/box cutter. Secure the 17mm nut onto the stud and close the lid.(fig2)
Located just to the left are the two 10mm bolts that hold the junction box to the alternator bracket. Remove one of the 10mm bolts and locate the ¼ ring terminals on the harness. Ground the wires using the 10mm bolt.
Located between the junction box and ground mounting point is a group of wires covered by loom. Open up the loom and locate the green wire. (The wire may be light green or have a white stripe as well. If one fan does not come on high speed the incorrect wire was tapped. To test the wire, a volt meter may be used to test for the presence of 12 volts when the truck is running and the AC clutch is engaged.)Using pliers, crimp the provided red tap to the green wire. Locate the green wire on the fan harness and attach it to the red tap. (fig3)
Remove the black cover from the PCM. This is done by pulling outward on the cover and clearing the two plastic tabs. Using a 7mm socket remove the blue PCM connector. This is the connector closest to the engine. Remove the grey retaining cover from the topside of the blue PCM connector. (If you have trouble removing the grey cover, simply use some pliers. A small flathead screwdriver can be used to pry the grey retaining tabs out.)Turn the connector over and using a thin pick or screwdriver, press on the white retaining tabs on each side of the blue-clear cover and remove it. Lubricate the blue PCM wire on the harness. Simply push it through pin 42 until it secures itself. Pull on the blue wire to ensure it is secure. Reinstall the blue-clear cover and grey retaining cover on the PCM connector. Reinstall the PCM connector.
Locate the LS1 fan connectors on the fan harness, install them and connect to the fans. Be sure to secure the wires with tie straps.
Using the supplied screws, attach the relay connectors to the upper left corner of the PCM cover. Be sure to clear the PCM when installing the screws.(fig4)
Flex-Fan or Universal Fans:
The fan harness will have four power wires coming from the relays. They are grouped in a wire loom and are attached to your existing fan motor wires using the supplied butt connectors and heat shrink. Be sure to cut the heat shrink to the appropriate size and install it over the wire before crimping the butt connector.
*Notice
The four wires are grouped in pairs. Each pair belongs to one fan. Do not tie the pairs together or swap wires.
Verify harness is installed correctly:
Start the truck and turn the AC on. As soon as the AC clutch engages, one fan will turn on high. When the engine coolant reaches the desired turn on value in the PCM, the other fan will turn on high. If the AC is off and the coolant reaches the turn on value, both fans will turn on low.
The relays don't plug into anything they just need to hang out, the PCM is in the fuse box
