Fat Jesus 808

iTrader: (5)

Before you scream at me, I've searched high and low and found a ton of different conflicting answers.

How are the stock fans in a 01 Z28 supposed to operate?

Currently mine has the passenger side fan comes on around 225, and shuts off at 21x. Thats all i've experienced with it. I have deleted the underhood A/C components. Today, I replaced the stock fans with 2 derale pushers using the stock fan controls to trigger the relays to the 2 fans. But still, only the passenger fan comes on at what i assume is high speed at 225ish.

01ssreda4

iTrader: (96)

That's correct for low speed activation. High speed doesn't come on till like 230ish. These engines were designed to run at those temps.

Fat Jesus 808

iTrader: (5)

I keep reading that at low speed, both come on but at 1/2 voltage or some crap?

Paul Bell

iTrader: (9)

LS1 F-body fan operation:

At low speed, the relays connect the fans in series which puts 1/2 voltage to both fans causing them to both run at 1/2 speed.

At high speed, the relays connect the fans in parallel which puts full voltage to both fans causing them both to run at full speed.

LT1 F-body fan operation:

At low speed one fan runs at full voltage causing it to run at full speed.

At high speed, both fans run at full voltage causing both to run at full speed.

Fat Jesus 808

iTrader: (5)

So if that's true, what could cause my ls1 fans to run like LT1 fans?

Paul Bell

iTrader: (9)

Either you have the wiring or the relays wrong.

Your opening post first says passenger fan works then you say the left fan works.

At any time, do both fans come on full speed?

Fat Jesus 808

iTrader: (5)

Sorry. Fixed. Only the passenger fan has ever came on. At 225ish and cools down and shuts off.

Fat Jesus 808

iTrader: (5)

So I unplugged the passenger side fan and at 235ish the drivers fan came on, I then plugged in the passenger side fan, both were running until it dropped back to 225, then only the passenger side was running until it dropped to 215. I'm gonna say they work fine and I'm just a dummy.

Thanks for the suggestions and insight on how they opperate.

Paul Bell

iTrader: (9)

It sounds like they're running LT1 style.

When these fans run, they're at full speed?

The PCM just sends out two grounds. The LT1 setup has two relays, the LS1 setup has three. It's the wiring harness that says how the fans operate.

Fat Jesus 808

iTrader: (5)

They seem to be full speed. Fairly loud and cools it down fine on the 1 fan.

Fat Jesus 808

iTrader: (5)

Maybe i'll try a new relay in the underhood unit. swap the 1 at a time?

Fat Jesus 808

iTrader: (5)

Another question,will the dual fan low speed setting work if there is no A/C?