Electric fan installation ~ on 2004 Silverado

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by Dustin2798, Jul 17, 2012.

  1. Dustin2798

    Dustin2798 New Member

    Looking to install and electric fan on my 2004 Silverado K1500 and have a couple questions. First, what kind of cfm and I looking for to keep the 5.3L sufficiently cooled?
    The other thing I was looking for advice on is setting the fan up to be automatically controlled. The wiring kits I have looked at come with temperature sensors, but where are they to be installed. I noticed a plug on the rear of the passenger head. Didn't know if this would be a possible place for the sensor? Any advice would be appreciated. Thanks.
    Last edited: Jul 17, 2012
  2. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    I'm in the midst of gathering required knowledge/items for an efan conversion on my 2004 GMC Sierra. To answer your questions (and then some):

    1. OEM efans on 2005's supposedly push about 10,000CFM. However, it should also be noted that 2005-2006 (and 07 classic) models also use a 34" radiator (compared with the 28" radiator on the 03-04 models), suggesting that the OEM efans require additional radiator surface area in order to properly cool the vehicle.
    2. LS1 fans will fit the 28" radiator that typically comes with the 1500 (measure yours to see if that's what you have), but will need some creative fabrication for an appropriate shroud ... and the LS1 fans may not offer adequate cooling when loaded or towing.
    3. The OEM 34" radiator with the OEM fans from a 2005-2006 (and 07 classic) model is likely the best option, as it was engineered for the truck and has a properly-shaped shroud.
    4. The computer is capable of controlling the fans. You'll need an OEM or aftermarket fan harness and a custom tune to enable this.
    5. If you're using a harness that utilizes a temperature probe, I've read that the probe is usually placed into the fins of the radiator as close to where the coolant enters the radiator as possible. As I've not done it I can't speak to the efficacy of this, it's just what I recall reading in my research.
    6. You might be cautious with Flex-A-Lite kits or, at a minimum, do some review research on them; I've read about some not-so-good things happening with them -- as in overheating.

    The following thread may also prove useful to you, as it's where a few folks are discussing efan conversions:
  3. Dustin2798

    Dustin2798 New Member

    will the 34" radiator in the 2005 silverados bolt right in and 04'?
  4. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    Supposedly it does. I haven't tried it yet, but I have a 34" rad sitting here. waiting for me to find out. I have a few projects ahead of my efan project, though...
  5. Dustin2798

    Dustin2798 New Member

    The radiator in my 04' measures 34", would the electric fan setup from the 05' bolt right up?
  6. Garas

    Garas New Member

    It should be, i did also a efans on my savana before. I'll message u the link on the other forum to give u a idea on how to do it. Its more better to have the efans electronically controlled by your pcm. It cost 150-200 to have it programmed. another $200 for the oem relay switch and probably $150-200 on the oem fans.

    Here's my efan setup on this thread:


    Last edited: Jul 24, 2012
  7. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    Blackbear Performance has an aftermarket relay switch that runs about 100...
  8. SuperDutyZ5.3

    SuperDutyZ5.3 New Member

    Once you get it mounted n fitting right, i like to use the temp switches that stick in the cooling fins and have the controll knob on the little box so its all self contained and all you have to do is tap into a hot wire.
  9. chevyrocker04

    chevyrocker04 New Member

    I plan to do the same thing. I have a factory electric dual fan and all the wiring to the fuse box n box it self, but very unsure on installation of the wiring. I don't want do burn something out if I do wrong. if I hook everything up correctly, your saying I just need to have my computer flashed?
  10. Tavo81

    Tavo81 New Member

    Get the flex a lite 280 pretty pricey but worth it I run those on my k1500 it took me like a 1 hr to install it pull around 5500 cfm there are nice

    Attached Files:

Share This Page

Newest Gallery Photos