Electric Fans on Monaro VXR ls2

[outtadrally]

Afternoon guys,
As always, I’m on the hunt for some info.

I noticed last weekend when driving around in circles over and over (just couldn’t decide where to go) that my car was starting to get warm. Never boiled or any where close but I’d imagine if they kept going in circles that would have been the next thing. It was also a very hot day so this may have been an additional factor.

Anyways, my question is:
I assume one of the electric fans is for the AC? I have my AC pump disconnected as it’s noisy but when I turn on the AC the fan doesn’t come on. Therefore wondering is this actually for AC. Just had a look today, the other fan wasn’t on either but the car wasn’t warm enough. Was thinking of wiring the AC fan to a switch for extra cooling for the next time I get lost and am going round in circles. Lastly which fan is AC, and which is for cooling.

Cheers

[NMNeil]

outtadrally said:

Afternoon guys,
As always, I’m on the hunt for some info.

I noticed last weekend when driving around in circles over and over (just couldn’t decide where to go) that my car was starting to get warm. Never boiled or any where close but I’d imagine if they kept going in circles that would have been the next thing. It was also a very hot day so this may have been an additional factor.

Anyways, my question is:
I assume one of the electric fans is for the AC? I have my AC pump disconnected as it’s noisy but when I turn on the AC the fan doesn’t come on. Therefore wondering is this actually for AC. Just had a look today, the other fan wasn’t on either but the car wasn’t warm enough. Was thinking of wiring the AC fan to a switch for extra cooling for the next time I get lost and am going round in circles. Lastly which fan is AC, and which is for cooling.

Cheers

I can only answer about the A/C in most late model cars. In the high or low pressure lines, sometimes both, there is a pressure sensor. If this sensor doesn't show a change in pressure when the A/C is turned on, then the A/C fans won't operate. And most cars use one fan for A/C in normal operation, but if the demand (system pressure) is high then it uses both.
It's a complicated system because when you floor the throttle the A/C will cut off to lighten the engine load, when you start the car with the A/C switched on the compressor won't start up until the engine is running over a certain RPM.
Lots of sensors, and a fairly complex BCM algorithm.

[vxr2010]

As above based on most cars , one fan ac one fan for engine , on my senator i deleted the ac as parts were difficult plus the cost of repair , i found an earth that triggered the ac fan to come on , it worked very well , it’s quite a draw of supply so don’t use thin wires , if ac is not working the fan won’t come on , if you are concerned about temps go into the engineering mode , on the monaro from memory push and hold two top buttons for dash display controls as you turn the car on from it being fully off , and you will get engineering mode , it will tell you correct coolant temp in degrees f plus other things

[outtadrally]

Not actually concerned with it overheating as it’s perfect on normal and even hard drives. It was been given some fair revs and abuse at the time so I would expect the temp to rise a bit on my quest to kill a set of tyres.

So if I simply disconnect the AC fan from the cars loom and wire it to a new switch and relay I assume this won’t upset anything? Or is the BCM or some other module looking for load when it expects the AC fan to kick in? Just don’t want lights to start coming on in the dash if I disconnect it. This is my only real concern. But then if I don’t turn on AC I assume this will never be an issue anyways?

Edited by outtadrally on Friday 21st May 18:28

[vxr2010]

if it was me then i would disconnect it in stages and see how i go , if you are doing it for good then worth removing every thing as it’s fairly heavy , the ac rad reduces the air flow quite a lot , i only deleted off the senator not done a monaro ,when my ac in the ls3 stopped working no dash lights were on it was just not working , so just remove in stages and check no cel’s on

[NMNeil]

outtadrally said:

So if I simply disconnect the AC fan from the cars loom and wire it to a new switch and relay I assume this won’t upset anything? Or is the BCM or some other module looking for load when it expects the AC fan to kick in?

Edited by outtadrally on Friday 21st May 18:28

A/C systems commonly leak out all the refrigerant over time. Hole in the radiator, leaking hoses, bad seals etc. so when it does happens it won't upset the BCM.
It will set code P0534 for loss of refrigerant and turn on the MIL light, but that's about all.

[stevieturbo]

Why not just fix the fan properly ?

[outtadrally]

stevieturbo said:

Why not just fix the fan properly ?

You have misunderstood. The fan is not broken. My question was relating to using the AC fan as an additional fan for purely cooling the engine, I.e it comes on at the same time as the engine cooling fan or be operated from a separate switch when it requires extra cooling.

My AC compressor is noisy and AC wasn’t working so I removed the drive belt as I don’t need AC anyway. Car was getting warm (not boiling) after some persistent donuts hence my question about the 2nd fan to allow for extra cooling. I just don’t want engine or warning lights coming on if I disconnect the AC fan from the cars existing loom and wire it as I mentioned above.

[fred bloggs]

Sometime when I go round and round like that, I get some squealing noise and smells from the rear of the car.

I have no A/C anymore. The belt was off as the compressor was noisy. I bought a Re-com compressor from Australia, and was fitting it up on the hottest day of 2018. It all went ok, so I went to fit the drier as well, and the fitting split in two . At that point I lost my rag and ripped it all out.
Problem solved.

If you get efi live , or get a remap, you can make the fan cut in at a lower temp, if you really want to.
Once when mapping on the road I had a belt come off at 6000 rpm, temps hit 120 , and it was ok.

Edited by fred bloggs on Friday 21st May 21:54

[outtadrally]

fred bloggs said:

Sometime when I go round and round like that, I get some squealing noise and smells from the rear of the car.

Lol mine does that too. Must be a common fault with the cars

So you removed compressor and everything and no lights or anything coming on!? I can’t see why they would but would rather be sure. I’d imagine it tidies up the engine bay quite a bit!

Have you disconnected the air con fan or wired it to work for engine cooling? Last question.... which fan is which? I’m gonna bring the car for a run tomorrow and get it warm so I will hopefully answer this myself as the one that isn’t running will be air con!

[Lincsls1]

outtadrally said:

So you removed compressor and everything and no lights or anything coming on!? I can’t see why they would but would rather be sure. I’d imagine it tidies up the engine bay quite a bit!

Although I don't know for sure, I'm pretty confident there is nothing that complicated or sophisticated on a Monaro that would cause any issue if you ripped the AC out. This is part of the beauty of them to me, nice simple cars with just the right amount of electronics to be modern and reliable, but not over needy.

[outtadrally]

Been looking on the Pontiac forums and studying the wiring diagram.

Seems both fans come on for cooling, either low speed or high speed. So no need for me to wire one to come on with the other. Must just take car out today and get it up to temp and ensure they are both working as they should.

If that’s the case, think I will rip out AC rad etc to just let some more air in as it’s not working anyways.

[fred bloggs]

Yes, basically everything A/C related in the engine bay is removed. No lights or problems.
Trimmed back the two wires to the compressor. As its only ever 30 degrees for 2 days of the year in the UK its not a problem. I thought it was misting up worse because of it, in winter, but turns out I had a swimming pool under the carpet. Glad ive got a garage for it now.

I should remove the evaporator too, but cant be bothered, too far under the dash.

[mfp4073]

fred bloggs said:

Yes, basically everything A/C related in the engine bay is removed. No lights or problems.
Trimmed back the two wires to the compressor. As its only ever 30 degrees for 2 days of the year in the UK its not a problem. I thought it was misting up worse because of it, in winter, but turns out I had a swimming pool under the carpet. Glad ive got a garage for it now.

I should remove the evaporator too, but cant be bothered, too far under the dash.

Swimming pool under tha carpet !!!!!
Was that air con related or water ingress from the door seal? If it's from the door I can tell you how I fixed mine if your still having problems.

John