Eletric Fans

DGrun22 · July 26, 2009

have a '99 silverado z71 5.3L, thinking about going with eletric fans, for all the obvious reasons. who should i go with flex-lite or perma cool, also anythat go off coolant temp or am i going to have to toggle switch it? also with the a/c pulling air across the condensor better off with a toggle swtich or is there wiring for that too?

96chevy7.4L · July 26, 2009

Hi forget perma-cool and flex-a-lite. Go with SPAL. they make the best fans and they last. SPal even makes a thermostat kit with the fan so it goes on and off on its own. They even make a over ride switch to where you can press a button and turn on manually if need be .

TexasAl · July 26, 2009

When I did this mod on my 95 Jeep, I went with a flex a lite setup. The best way to go is with a thermostat switch. You can purchase the adjustable one so that you can set it at the desired temp.

Jennabear · July 26, 2009

I would disagree, the best way is to have it work as if they were stock, thus having the fans work off of the PCM. This way you will reap the full benefits and not have to worry about too much draw on the alternator.

TexasAl · July 26, 2009

I would disagree, the best way is to have it work as if they were stock, thus having the fans work off of the PCM. This way you will reap the full benefits and not have to worry about too much draw on the alternator.

What do you have to do to have the PCM control electric fans? If he is pulling his mech. fan, I thought the only option would be to use a thermostat switch. How hard is it to run off the PCM? Any info would be great to know for future reference.

Al

Jennabear · July 26, 2009

The vehicles that have the efans stock, use a harness that connects the fans to the PCM at PINs green 33 and blue 42. Those PINs would need to be turned on in the PCM on vehicles that did not have stock efans and a harness would also need to be purchased/made. This would allow for more efficiency than just running off of a thermostat switch.

Spurshot · July 26, 2009

"...thinking about going with eletric fans, for all the obvious reasons. ..."

I have a 99 2500 6.0 L that I've towed with and off-roaded with in 100f plus temps. Neve had a overheat problem. What problem are you having? The most common problem with the OEM engine driven fans is that the clutch goes bad and no longer engages. This often can happen from 50,000 miles to 100,000 miles. A new clutch is an easy fix and not all that expensive. That said, I need to check my 99 to see it's working still working properly. It's been 70-90k miles since I replaced it.

TexasAl · July 26, 2009

The vehicles that have the efans stock, use a harness that connects the fans to the PCM at PINs green 33 and blue 42. Those PINs would need to be turned on in the PCM on vehicles that did not have stock efans and a harness would also need to be purchased/made. This would allow for more efficiency than just running off of a thermostat switch.

Cool. Thanks for the info. I wonder if I could do the same on a Jeep. I'm thinking of getting another Jeep as a project, and it would be pretty cool to get the e-fans working off the pcm. Thanks Jennabear!

Al

DGrun22 · July 26, 2009

yeah i dont have a prob with stock fan clutch its working like it should, just want less drag on the motor better gas mileage in the summer, espcially living in texas where it feels like the fan is fully in engaged all the time on those 100+ degree days, i think jenna bear said it about the ecm being set for e-fans, can that be done with a tech 2 scanner from gm, and will this also kick the fans on when the a/c is on for the condensor?

DGrun22 · July 26, 2009

oh and what about towing can most efans handle it

Jennabear · July 27, 2009

oh and what about towing can most efans handle it

PM answered. No problems here towing with efans. We have towed with the SSS 4 times cross country and the Tahoe has towed many a trailer as well. The TBSS will soon be getting the efan upgrade.

Spurshot · July 30, 2009

The Jeep application is a very good one for E-fans. Slow going with little air movement. But the engine driven fans with the clutch usually have higher CFM capability. If the clutch isn't disengageing, it could either be the clutch is bad or it's hot enough it should be engaged.