GM OEM eFans vs Flex-a-lite question

[iamdub]

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.

PCM-controlled is best, but a sensor that directly reads the coolant temp just like the factory sensor is second best. There are aftermarket sensors that screw into unused/blocked-off ports in the coolant jackets, just like the factory one in the cylinder head. The radiator fin probes are 'okay' if you have it on an adjustable controller since that can be adjusted for any inaccuracies in temperature reading.

 

[ivin74]

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!

I put the flexlite fans on my 03 Silverado SS and they worked great, the only thing I didn"t like was that they were freaking loud. The only issued I ran into was the wiring got hot and melted the fuse that came with the fans. I replaced the fuse with one of those they use for amplifiers. This was back in 2007, flexlite might have already fixed that flaw.



https://www.amazon.com/Rockford-Fos...ocphy=1026681&hvtargid=pla-571240275103&psc=1

 

[Karlus]

Im just concerned about messing with the PCM wiring.

You are knowledgeable and being new I respect that greatly. Do you have a recommendation on a radiator probe and controller? Im happy to do my own research, but if someone had success I would be interested.

Thanks so much

 

[iamdub]

Im just concerned about messing with the PCM wiring.

You are knowledgeable and being new I respect that greatly. Do you have a recommendation on a radiator probe and controller? Im happy to do my own research, but if someone had success I would be interested.

Thanks so much

My experience with a controller was with the Ford Taurus fan I had on my S10. I used a Flex-A-Lite #31165 Variable Speed Controller. I went with this one because it started the fan at 60% power then ramped up the power/speed as needed (if needed) to greatly reduce the load on the charging system. It also has a 45-amp capacity. I had it adjusted to turn the fan on at just a hair under 210, going by the dash gauge. I don't know if it wasn't available then or I just didn't know about it, but they have a temperature sensor version, part #31163. I definitely would've gotten that one. The probe style worked fine for me, but there are still variables that can affect it's readings. I'd get the thread-in sensor style and screw the sensor into the plugged-off port on the passenger head.

I have no experience with it, but they have a much cheaper controller, #31147, that's just a simple adjustable controller with a probe sensor and 20 amp capacity. This one should definitely be used to trigger a high-amp relay because a single fan sufficient enough for a 5.3 will pull much more than that. You'd also tap the relay into the A/C compressor clutch wire (use a diode!) so it triggers the fan when the A/C is on. Next up from that one, and simplifying things, is the #31149. It has a 40 amp capacity and an A/C trigger input. I don't know what amperage an OEM fan draws, so I can't say if this one has enough ampacity.

 

[Karlus]

Awesome. I love these solutions. Let me see what I can pull together

 

[Rocket Man]

There’s a tech section thread on this with a walkthrough for using the pcm and a lot of information. There’s a couple pins to install in the PCM harness but it’s detailed in the thread. You also need to have a tuner turn on the function. It’s not hard, but if you go that route I suggest having the pins turned on before you do the mod so it’s ready to go.