2003 Suburban EASIEST EFAN Swap Ever!!

[summithighrise09]

So I've been looking thru posts of people going to the junk yards to source efan swap kits out of 2005-2006 trucks and such to ditch their Clutch Fans with. I havent seen much on Nelson Performance's Wiring Harness kits so I decided to make one. I have a 2003 Suburban that came with clutch fans and I used LKQ sourced 2009 model fans with more blades. I mentioned 7/9 in the video but its actually 5/7 blades. This is the fastest and cleanest install you can do, IMO, as opposed to sourcing fuse blocks and such from the local junkyard. Here's the link to the wiring harness and I'll include the directions showing which pin numbers to connect to.
HOPEFULLY an Admin can STICKY this.
Thanks
Cam

GM OEM Truck/SUV Efan wiring harness

This e-fan harness works with 99-2006(07) GM Truck/SUV, using the GM Truck/SUV OEM e-fan assembly.It allows the use of electric fans on a full-size GM Truck that was originally equipped with a clutch fan.Your vehicle must be equipped with the larger radiator. The GM OEM e-fan fits the larger...

nelsonperformance.com

 

[Rocket Man]

Unfortunately plenty of people have had aftermarket harnesses, including Nelson’s, melt in situations where the weather is real hot. I had this issue with my LS1fans.com harness. It stranded me 100 miles from home in 100* heat. Some people have had good luck. Myself, I’ll never do anything other than an OEM setup. It’s never even got more than warm since I installed the factory box with its relays and fuses. It’s a better design. Just a heads up.

 

[summithighrise09]

Unfortunately plenty of people have had aftermarket harnesses, including Nelson’s, melt in situations where the weather is real hot. I had this issue with my LS1fans.com harness. It stranded me 100 miles from home in 100* heat. Some people have had good luck. Myself, I’ll never do anything other than an OEM setup. It’s never even got more than warm since I installed the factory box with its relays and fuses. It’s a better design. Just a heads up.

I can’t speak to that because I’ve had 4 harnesses. 4 different trucks. 4 totally different years. I’d carefully say they were possibly installed insufficiently. Maybe. Maybe not. No way to know probably.
thanks
Cam

 

[Rocket Man]

I can’t speak to that because I’ve had 4 harnesses. 4 different trucks. 4 totally different years. I’d carefully say they were possibly installed insufficiently. Maybe. Maybe not. No way to know probably.
thanks
Cam

That’s what Nelson and the others always blamed it on, installer error. Except there’s pretty much zero to go wrong with the install. One power wire, right to the main positive battery connection, one ground wire to the frame, one trigger wire. The other two are the plugs on the fans. It always seems to be hit or miss. There’s a few members here who had theirs melt too. I even rebuilt mine with 60 amp relays and relay block and heavier gauge wire. It started melting the heavier relay block. The fans never failed to run after I upgraded everything but the partial melting of that block was the last straw. Maybe my fans drew too much power but they were the same ones many others used. Maybe the location where those relays are mounted was the issue, too close to the radiator. Either way, the only thing I changed was the harness to an OEM one and no problems since. If you do a Google search for this issue you’ll find it’s not so rare.

 

[summithighrise09]

That’s what Nelson and the others always blamed it on, installer error. Except there’s pretty much zero to go wrong with the install. One power wire, right to the main positive battery connection, one ground wire to the frame, one trigger wire. The other two are the plugs on the fans. It always seems to be hit or miss. There’s a few members here who had theirs melt too. I even rebuilt mine with 60 amp relays and relay block and heavier gauge wire. It started melting the heavier relay block. The fans never failed to run after I upgraded everything but the partial melting of that block was the last straw. Maybe my fans drew too much power but they were the same ones many others used. Maybe the location where those relays are mounted was the issue, too close to the radiator. Either way, the only thing I changed was the harness to an OEM one and no problems since. If you do a Google search for this issue you’ll find it’s not so rare.

I definitely don’t doubt what you’re saying. I’ve just never had that issue. I’ve always made sure they got a good ground and good connection to the power box. But you’re right there are sooo many different ideas in what could’ve gone wrong.
Thanks
Cam

 

[tRidiot]

I had one of those harnesses, it melted. We made one, it works fine.

 

[fasteddy]

I'm looking to do the efan upgrade. I haven't yet as I've seen the torment from others.
I've read and seen on YouTube where people get so frustrated with failure they just go back to the mechanical fan.
Does anyone have a good parts list for the efan upgrade?
I don't mind buying new parts.

What fans? from what year?
Does the radiator need to be upgraded?
OEM? Harness? Where do I get that?
What else do I need?

 

[Rocket Man]

I'm looking to do the efan upgrade. I haven't yet as I've seen the torment from others.
I've read and seen on YouTube where people get so frustrated with failure they just go back to the mechanical fan.
Does anyone have a good parts list for the efan upgrade?
I don't mind buying new parts.

What fans? from what year?
Does the radiator need to be upgraded?
OEM? Harness? Where do I get that?
What else do I need?

Fans from 05-06 Tahoe. New or junkyard. Radiator needs to be the 34”, most are but double check. I highly recommend an OEM harness, 05- 06, possibly can get one from @ScottyBoy or wrecking yard/EBay. Here’s a good thread on it.

How to install E-Fans

Step 1 - Pop hood Step 2 - Remove intake tube (This is only IF you want extra space...I didnt pull mine this time but you might want to) Step 3 - Remove two top bolts and pull coolant line clip out of shroud Step 4 - The Fan Shroud is two pieces. A top and a bottom. They are connected...

www.tahoeyukonforum.com

And you will need to have a tuner turn on the pin on the ECM. If you have HP Tuners you can do it, or anybody that does tunes can.

 

[Tonyrodz]

NNBS fans will also fit. Iirc up to at least 2014.

 

[S33k3r]

Fans from 05-06 Tahoe. New or junkyard. Radiator needs to be the 34”, most are but double check. I highly recommend an OEM harness, 05- 06, possibly can get one from @ScottyBoy or wrecking yard/EBay. Here’s a good thread on it.

How to install E-Fans

Step 1 - Pop hood Step 2 - Remove intake tube (This is only IF you want extra space...I didnt pull mine this time but you might want to) Step 3 - Remove two top bolts and pull coolant line clip out of shroud Step 4 - The Fan Shroud is two pieces. A top and a bottom. They are connected...

www.tahoeyukonforum.com

And you will need to have a tuner turn on the pin on the ECM. If you have HP Tuners you can do it, or anybody that does tunes can.

Can you turn the pin on with a Tech2?

 

[Rocket Man]

Can you turn the pin on with a Tech2?

No. Only tuning software like HPT or EFI Live or similar. It wasn’t an option until the 05 MY and the Tech2 knows what year your truck is. All it can do is flash the PCM to stock.

 

[S33k3r]

Thanks!

 

[MassHoe04]

I'm new to Chevy's and maybe it is different here, but I can share what usually came up on the Wrangler Forum while I had my 05 Rubicon...
Many people, who converted from stock fan/clutch to electric fan(s), went searching junk yards and Ebay for original stock fans to put back in.

Main reasons included:
Engines ran hot, because more fan blades blocked air flow at highway speeds.
-or-
Electric fan motors did not like getting wet, when off-roading. Overheat situations caused when water killed the fan motor.
-or-
The electric fan motor just burnt out.

The engineers specifically designed a fan with X number of blades, of s certain dimension and pitch for maximum flow and cooling.
Sometimes, more is not better.

Fan clutches can fail. But they are usually good for a lot of miles before they do.

While fording big puddles or deep water can raise havoc with other components, if swamped bad enough...
Mechanical or thermal fan clutches don't care if they get wet. One less component to worry about, should you hit water on the trail with good old fan clutch setup.

Having just come from the Jeep, it seems that a lot of people agreed that is was often best to stick with factory stock radiators and fan components.
I don't think I would be one to go with a conversion to electric cooling fans on my 04 Tahoe. I'll keep that all factory.

To each, his (or her) own... Vehicle upgrades and accessories are very-much a personal thing.

 

[Rocket Man]

Lol Jeep people.

 

[S33k3r]

GM converted to e-fans in 2005 for most consumer vehicles on the GMT800 platform (of which your 2004 Tahoe is a member). They kept the clutch fan set up on the 3/4+ ton vehicles, however. Most folks working with the 1/2 ton vehicles like the efans because they cool better in the majority of driving conditions consumers find themselves. Further, som engine builders like them as well. If nothing else, you will get consistently better use out of your air conditioner if you have efans than if you have clutch fans. After that, for anything that didn't come stock with an efan -- it is up to the owner's preference. But I don't think you are going to face the issues you are suggesting with the OEM fans.

 

[Rocket Man]

GM converted to e-fans in 2005 for most consumer vehicles on the GMT800 platform (of which your 2004 Tahoe is a member). They kept the clutch fan set up on the 3/4+ ton vehicles, however. Most folks working with the 1/2 ton vehicles like the efans because they cool better in the majority of driving conditions consumers find themselves. Further, som engine builders like them as well. If nothing else, you will get consistently better use out of your air conditioner if you have efans than if you have clutch fans. After that, for anything that didn't come stock with an efan -- it is up to the owner's preference. But I don't think you are going to face the issues you are suggesting with the OEM fans.

Unless you’re wading rivers. At which point there’s plenty of other things that are going to get wet.

 

[MassHoe04]

GM converted to e-fans in 2005 for most consumer vehicles on the GMT800 platform (of which your 2004 Tahoe is a member). They kept the clutch fan set up on the 3/4+ ton vehicles, however. Most folks working with the 1/2 ton vehicles like the efans because they cool better in the majority of driving conditions consumers find themselves. Further, som engine builders like them as well. If nothing else, you will get consistently better use out of your air conditioner if you have efans than if you have clutch fans. After that, for anything that didn't come stock with an efan -- it is up to the owner's preference. But I don't think you are going to face the issues you are suggesting with the OEM fans.

Thanks! That is helpful information. Still getting educated on GM stuff...

 

[Rocket Man]

The AC condensers on the GMT800 platform seem to be inadequate, at least when combined with the clutch fan. I know mine sucked in stop and go traffic, now with e fans it works way better. It used to start blowing hot air if the ambient was 95 or above and I wasn’t moving to keep airflow going. Now it rarely ever does that. GM did address the problem prior to going to e fans by issuing a TSB which called for installing an auxiliary electric fan directed at the condenser but it was a PIA to install and wire in. It wouldn’t work on mine due to the intercooler for my supercharger anyway. There’s other pluses to the e fans as well- more room up front and easier to work on the front of the engine, a few more hp, cleaner look, etc.

 

[mattt]

NNBS fans will also fit. Iirc up to at least 2014.

Will the NNBS fans from 07-14 bolt up the same as the 05-06 factory fans? Would you happen to know if the plugs are the same for NBS 05-06 fans and 07+ NNBS fans? Asking all this because I just found a clean set of NNBS fans in a pick your part and considering bringing them home and going about the conversion.

Is the factory relay block, fan controller the same between 05/06 and 07 and later? I already have the fan controller/relay block from a 2005 Tahoe, but had not picked up the fans & shroud yet.

I seem to remember that the 07+ E-fans were superior to the earlier 05/06 for some reason I can't recall????
Thanks all.

 

[Tonyrodz]

Will the NNBS fans from 07-14 bolt up the same as the 05-06 factory fans? Would you happen to know if the plugs are the same for NBS 05-06 fans and 07+ NNBS fans? Asking all this because I just found a clean set of NNBS fans in a pick your part and considering bringing them home and going about the conversion.

Is the factory relay block, fan controller the same between 05/06 and 07 and later? I already have the fan controller/relay block from a 2005 Tahoe, but had not picked up the fans & shroud yet.

I seem to remember that the 07+ E-fans were superior to the earlier 05/06 for some reason I can't recall????
Thanks all.

Sorry, I don't know 1st hand(I actually read about the fitment on tyf), but I'd guess yes--that they bolt up the same, and the plugs are most likely the same--if not that's easy enough to swap. I don't know about the rest tho. Hopefully someone more knowledgeable will chime in.