GM OEM eFans vs Flex-a-lite question

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Karlus

Member
Joined
Nov 10, 2019
Posts
52
Reaction score
49
I have an 03 Tahoe.

I'm wanting to switch the clutch fan out for electric. I've seen info for using the OEM Silverado dual fan and turning the fan on in the computer. Understood.

What is the difference between these fans and the Flex-a-lite fans (besides cost)? My undertanding is the Flex-a-lite will draw 28 amps at full tilt boogie. Means new hi-po alternator.

Are the OEMs less powerful? Anyone know the differences?

Thanks!
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
19,148
Reaction score
25,185
Location
Treasure Coast, Florida
I have an 03 Tahoe.

I'm wanting to switch the clutch fan out for electric. I've seen info for using the OEM Silverado dual fan and turning the fan on in the computer. Understood.

What is the difference between these fans and the Flex-a-lite fans (besides cost)? My undertanding is the Flex-a-lite will draw 28 amps at full tilt boogie. Means new hi-po alternator.

Are the OEMs less powerful? Anyone know the differences?

Thanks!

Try and compare wattage too. On the later generation, we have 500 watt fan motors and 700 watt fan motors.

Thirty years ago I put a Black Magic Flex-A-Lite fan on one of my cars and it kept those two race cars cool for many years. Having said that, my preference is almost always towards OEM parts.
 
Last edited:

iamdub

Full Access Member
Joined
Apr 23, 2016
Posts
20,780
Reaction score
44,687
Location
Li'l Weezyana
My short and simple reply is that OEM fans are designed to work with the rest of the OEM system (the physical fitment to the rad, alternator's output, PCM control, etc.) and do so for 100,000+ miles. Good aftermarket fans are designed to last "a while" (at least, longer than the competitor), but are only warranted for 90 days, maybe a year, maybe two years. The OEM fans are guaranteed to fit and be the easiest to implement.
 
OP
OP
Karlus

Karlus

Member
Joined
Nov 10, 2019
Posts
52
Reaction score
49
Agreed. So reading between the lines: the stock alternator will work with the OEM fans and that means less amp draw but less "performance."

The aftermarket fans seemed a bit high at 27 amp draw and I would imagine are for performance or forced induction engines where extra power is required.
 
OP
OP
Karlus

Karlus

Member
Joined
Nov 10, 2019
Posts
52
Reaction score
49
I am also wondering about the hassle of using the PCM to control the fans vs just using a temperature sensor near the inlet side of the radiator to control the fan speed. I don't have a programmer yet, and would like to avoid buying the hptune right now.
 

NoReverseYukon

Full Access Member
Joined
Feb 27, 2019
Posts
557
Reaction score
1,226
Location
NE Wisconsin
Just a quick search shows that 2003 Tahoes had both 105 amp and 145 amp alternators. I suspect you'll need the 145 amp if you want to install e-fans.
I got lucky - found the fan,wiring harness, and HD alternator on same vehicle in salvage yard. Haven't gotten around to installing them yet.
 

BG1988

Full Access Member
Joined
Nov 14, 2018
Posts
2,949
Reaction score
1,344
good choice with the oem the op should go with oem
 
Last edited:

iddqd

Full Access Member
Joined
Dec 18, 2017
Posts
224
Reaction score
650
Location
San Francisco, Comifornia, USSA
My short and simple reply is that OEM fans are designed to work with the rest of the OEM system (the physical fitment to the rad, alternator's output, PCM control, etc.) and do so for 100,000+ miles. Good aftermarket fans are designed to last "a while" (at least, longer than the competitor), but are only warranted for 90 days, maybe a year, maybe two years. The OEM fans are guaranteed to fit and be the easiest to implement.

This is true not just for fans, but for everything aftermarket :)

With some exceptions of course, like OEM suppliers for example
 

iamdub

Full Access Member
Joined
Apr 23, 2016
Posts
20,780
Reaction score
44,687
Location
Li'l Weezyana
Agreed. So reading between the lines: the stock alternator will work with the OEM fans and that means less amp draw but less "performance."

The aftermarket fans seemed a bit high at 27 amp draw and I would imagine are for performance or forced induction engines where extra power is required.

I'd aim for an AD244 (180A). But, yes, a stock high-output alt instead of the stock standard (105A) alt.

"Less performance"? Depends on how you look at it. In this case, less is more. An aftermarket fan is gonna be designed to meet and exceed most needs so a given fan can be used across a wide spectrum of applications. It's also intended to cover those modified applications where an OEM fan is inadequate. If it's too much for a particular setup, it'll simply be ran for shorter amounts of time or be slowed down if it's on that kind of controller. It'll still be pulling excess amperage, but that's the nature and it'll have to be addressed elsewhere. OEM will select a comparatively less powerful fan because anything more is excess and just presenting extra, unnecessary load on the charging system.
 

Forum statistics

Threads
129,262
Posts
1,812,985
Members
92,364
Latest member
Ep33401
Top