Cooling fan description & diagrams (service manual) - Third Generation F-Body Message Boards

Reid Fleming · 12-11-2006, 10:10 PM

Here are some pictures to help you diagnose your cooling problems. At the very least, it's a handy way to learn how the system works.

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IROCWPB · 12-26-2006, 10:30 PM

I found this post very helpful in trying to un-rig my radiator fans. The previous owner had them setup to run whenever the ignition was on. I'm using chart C-12 to try to figure out why neither of the signal wires are grounding the relays to turn the fans on. The chart refers to a diagnostic test port as well as multiple circuits, but I'm not sure where they are. is there another page you could scan that lists their location? Also, what book are you taking this from? I think I'd very much like to have it.

Thanks
Justin

edit: also, I can't find my A/C Pressure Fan Switch, it's not in the location shown near the top of this page. Any help finding it along with the sensor that tells the ECM the coolant temp on an 88' 5.7L IROC (i've read that it's somewhere around the thermostat and it's three wires.) would be great.

coolram62 · 12-26-2006, 10:58 PM

That is a good piece of info for troubleshooting.IROCWPB it looks to be out of a Camaro/Firebird factory service manual or TSB because of the date in the lower right corner

IROCWPB · 12-26-2006, 11:04 PM

I wanna know exactly what it is because it seems it's written for idiots like me

I have alot of un-rigging to do in this car between the electrical and the A/C.

Reid Fleming · 12-27-2006, 11:39 AM

Hi guys, I saved these pages off another message board quite some time ago. It was from a guy with a 1991 model.

At the time I was trying to figure out when and why the 2nd fan turns on. Mine had never turned on even after sitting in traffic for 30 minutes in the summer. (Turns out the car just wasn't getting hot enough to turn it on)

I don't think I have any more pages. I'll look when I get back home from the holidays.

IROCWPB · 12-27-2006, 04:27 PM

I have narrowed it down to being a "GM Service Manual" "Carline Manual" or "Helms Manual" lol

I did some googleing and three different forums called it three different names. I think Helms might be reprinting the factory manual though, not sure where Carline comes from though, although the sheets above do say carline on them.

coolram62 · 12-27-2006, 11:14 PM

I believe the "Carline" referred to on the pages is meant as "F" Body Carline.

IROCWPB · 03-15-2007, 08:20 PM

This should be a sticky.

IROCWPB · 03-15-2007, 08:49 PM

Could someone post the voltages at the relays with the ignition on, engine off, cold car?

my green/white wire (primary relay signal) has 0v
my gray wire (secondary relay signal) has 7.5v
my brown wire (ignition power i guess) has 12v

is something wrong here? why would i be getting 7.5v? I'm trying to diagnose why only one fan will run while they're both hooked up, but either will run if the other is unplugged at the relay.

edit: also, where's the bulkhead connector (G8) supposed to be? I honestly don't even know what a bulkhead connector is, but there's no brown wire running up my frame rail for me to follow.

IROCWPB · 03-15-2007, 09:35 PM

I hooked both relays up to the green/white signal wire and everything is working great now. Still not sure why the secondary fan's signal wire has 7.5v on it. Although now my fans are coming on very early, like before 160* which I don't mind one bit, I just have to put a lower temp thermostat in it and I'll probably drill it.

GMan 3MT · 03-19-2007, 10:42 PM

Quote:

Originally Posted by IROCWPB

I have narrowed it down to being a "GM Service Manual" "Carline Manual" or "Helms Manual"

That's definetly from the factory service manual.

Quote:

Originally Posted by IROCWPB

Also, where's the bulkhead connector (G8) supposed to be?

That's referring to the C100 bulkhead connector, the big honkin thing with all the wires running to/from it under the fan relays on the driverside firewall. G8 is the location of the brown wire... think of a grid made up of rows A-G and columns 1-8

RebelGQ · 04-13-2007, 09:31 PM

Does anyone know the name of the wire/cable that runs from the radiator to the end of the motor block (left side?)

kretos · 05-11-2007, 01:51 AM

this should be stickied

JB22 · 05-11-2007, 08:30 AM

Yes thats factory service manual. I have one and I am just now learning to reap the benefits. Got it and the electric diagnosis for like 40 bucks on ebay.

87 IROC NC · 05-07-2008, 04:53 PM

Best thing I ever bought, I got it right after I got the car and it has info for just about anything

Canadianguy2006 · 09-28-2009, 07:30 PM

quick question here, i have deleted the AC out of my car and all the wire connectors are hidden from water (not plugged in), did i just basically kill any chance of the secondary coming on? or is there a secondary system that comes on even with out the AC? i know that the relay is probably shot but just wanted to ask first before getting a new relay

Reid Fleming · 09-28-2009, 07:58 PM

Even with no A/C, it should still turn on when the passenger head fan switch gets to the turn on temperature. A 1LE car for example would still have the passenger fan turn on when the coolant temp gets to 235°F, assuming everything is stock.

Now in Ontario in late September, your chances of the car getting to 235° are slim to none. So your fan will appear to not work. But in reality it will work if the car ever does get up that hot.

Canadianguy2006 · 09-28-2009, 08:36 PM

how the heck did you know i was from Ontario?? lol hehe well it hasn't worked all summer, so i'm assuming that the relay is shot(maybe), hasn't been replaced in a while, could also be the temp switch has gone bye bye, should have had it replaced when i did the coolant flush last year :P oh well next time