Left fan turns on as soon as ignition is turned on

Reply Subscribe

Thread Tools

Search this Thread

May 12, 2012 | 07:40 PM

djmarch

Thread Starter

Member

iTrader: (4)

Joined: Nov 2003

Posts: 266

Likes: 1

From: Mid Mo.

Car: 1989 GTA - Gunmetal grey

Engine: 5.7 ltr.

Transmission: 700R4

Axle/Gears: 3:27 9 Bolt Borg Warner

Left fan turns on as soon as ignition is turned on

Hmmmm....Fired up my GTA today and noticed when I turned the ignition switch, (before it turned over), I heard a fan turn on. Got out, lift the hood and sure enough, with the engine not running and the ignition switch on, the left coolant fan was running. Somewhere in the circuit I'm getting 12 volts to the fan as soon as the ignition switch is turned on, bypassing the temp switch. Any recommendations out there on where to start troubleshooting ? A bad relay ? A bad temp switch ? All recommendations appreciated..

May 13, 2012 | 05:36 PM

tom86iroc

Senior Member

iTrader: (1)

Joined: May 2008

Posts: 867

Likes: 1

From: pawtucket RI

Car: 1986 iroc

Engine: alum. head 350 supercharged

Transmission: 6speed

Axle/Gears: ford 9in 3.90 35 spline moser axles

Re: Left fan turns on as soon as ignition is turned on

could also be a ground wire is touching bare metal somewhere u have 2 power wires one from the batt constant power and the second is switched power from your ign switch

May 13, 2012 | 07:58 PM

eseibel67

Supreme Member

Joined: Jul 2009

Posts: 2,328

Likes: 9

From: Kitchener, ON

Car: 1988 GTA

Engine: LB9

Transmission: T5

Axle/Gears: 3.45

Re: Left fan turns on as soon as ignition is turned on

Left as when you sitting in the driver's seat? Either fan could run if the relay is jammed.

If it's the passenger side fan, there is also a possibility that the switch in the head is stuck in the "ground on" position.

May 14, 2012 | 09:55 AM

NINÅ

Supreme Member

Joined: Jan 2006

Posts: 3,341

Likes: 10

From: Mooresville NC

Car: LOWERED ♦ CRIMSON METALFLAKE

Engine: ► 400 KUBES ◄

Transmission: 765R4

Axle/Gears: EATON POSI 4.56

Fan Plan

You didn’t say if you just bot the car which can mean the PO rigged the wiring that way.

However if the wiring is stock, on a cool engine it shouldn’t be on unless AC or front defog is selected.

◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙

How Come Some Drivers On The Street Don’t Know How To Make A Turn In One Direction Without Starting By Turning In The Opposite Direction?

May 14, 2012 | 07:35 PM

djmarch

Thread Starter

Member

iTrader: (4)

Joined: Nov 2003

Posts: 266

Likes: 1

From: Mid Mo.

Car: 1989 GTA - Gunmetal grey

Engine: 5.7 ltr.

Transmission: 700R4

Axle/Gears: 3:27 9 Bolt Borg Warner

Re: Left fan turns on as soon as ignition is turned on

Thanks for all your input guys..I knew as soon as that fan turned on with the ignition switch that something isn't right. It's the driver's side fan..It's funny, because it just started doing it...OK now..I'll throw one at you all since we have some questions on which fan comes on first as even myself haven't quite figured it out for sure. A source awhile back told me that the front coolant temp switch that mounts below the thermostat turns on the left fan @ 195. (The spec of the stock thermostat). The second temp switch, located below the passenger side head turns on the second fan at 230 there abouts give or take a few degrees. Also I heard turning on the AC switch will turn the fans on. Both of them ? Or just one ? Which one ?
Anyone seeing where I'm going with this ??? I've heard so much mixed info on this subject, like it's the right fan that turns on first, No it's the left etc...etc..So..I'll go back to my original question I had months ago...Does anybody really know the circuit logic on these cooling fans on how they are suppose to operate ? I believe this would be good info for all of us when troubleshooting these TPI engines...