cold air intack for air vents

[aj_vmax]

Hello guys I have a problem with my fresh air on the heater system. We can have it on dead cold and warm air flows in. Just not sure wear to start. Any help would be good. Was thinking that it is the flappy thing in the heater exchange.

[Sir Roofy]

Have a look at the and see if a/c clutch
is engaging on the pump

[BigRAWesty]

Yep, good start.
Do the gu's run wire controls or electric??

[aj_vmax]

The a/c works its just when u have fresh air u get warm air coming in vents

[mudski]

Mines the same if it's a warm day. Check the cable that changes the temp from hot to cold first. But in my case I think it's where the air comes in from get extra warm from the engine bay too....

[happygu]

Aj,

It is a GU Patrol thing, as it has happened on all of mine....

I also think it is a modern car design thing too, as most modern cars are like this too, and I think it is expected that we use the AC all the time.

The are some that have checked this and modified intakes / covered components with varying results but I haven't seen it here .... do a search on the www and see what you can find

Mic

[Robo]

cold air position selected and hot air coming in would only mean 1 thing.
it's stuck on hot.
"edit above", seem this is incorrect after reading maccas input on hot air bypassing doors and finding it's way into the cab.
always learning something, thanks macca

or a very hot day dash and vents can take a long time to cool down.
fast moving air can take longer to cool system than a moderate flow.

before heater box there is a flappy door that directs air either through heater or closes to by-pass the heater when controller is moved to cold position, simple design but works well.

If you have a cable set up you should feel some resistance when you move lever hot to cold etc,
and move fast enough will hear door slam closed in either direction.
vac or elec system harder to audibly tell.
cables have a habit of coming loose, struck this a couple times, & a broken vac actuator line once.

what yr & model car exactly ??

[aj_vmax]

thanks guy I have a 2001gu 4.5ltr wagon.

[macca]

You said warm air not hot, my findings;
Mine does it too, a GU as well.
I thought it was from the flap not sealing and have tried fitting springs etc. to make it close better, that didn't work.
I fitted a electrically operated ball valve on the heater circuit to stop hot water entering the cabin and it still gets hot air from the vents inside the car.
So I should have no heat from the coolant circuit.
What I have figured out it comes in from the vent at the bottom of the windscreen drawing fresh but warm air over the bonnet.
Travelling slow it is really quite bad, travel a bit faster and it's not so noticeable. Heat also enters the car via the floor and firewall too.
At this point I have given up and live with it, turning the A/C on now and then if it gets bad.

[Robo]

thanks guy I have a 2001gu 4.5ltr wagon.

Does it have
climate control or manuals dials?.

macca states heat enters anyway after fixing door, mine maybe suffering same problem.
have only just purchased it, but car seem a bit to warm when set to ambient temp fresh air only!
humm.
when I get time me looking also

[macca]

I haven't tried it, putting some masking tape over the inlet at the bottom of the windscreen might prove my theory.

[threedogs]

might need to put some heat shield on the fire wall to eliminate
any radiated heat, someone just did it with great results

[aj_vmax]

Robo it has dials. I will be pulling al under dash out as now the fan is making noise will post when I get in there

[Robo]

Robo it has dials. I will be pulling al under dash out as now the fan is making noise will post when I get in there

looking at Nissan fast at what's connected where, schematics may help you out seeing what goes/connects where etc.

[aj_vmax]

Thanks again guys. All is working like it should. Flap opens and closes like it should. As for the noise it was a plastic bag .that had sux up into the fan area. Will be looking for a mod for fresh air vent

[aj_vmax]

Hey guys I got into under the dash everything is working under the dash. Will have to look at a mod to get fresh air into the vents

[Chubba]

I haven't tried it, putting some masking tape over the inlet at the bottom of the windscreen might prove my theory.

Has anyone tried macca's theory out with the tape? It's an interesting one. Will try it myself if not.

[Ghosts]

I remember a brother having an XC Falcon, which had vents near the feet on the passenger and drivers side, that had a black handle that you pulled towards the seats and what a difference it made, by letting the cool air in.

[Brissieboy]

I remember a brother having an XC Falcon, which had vents near the feet on the passenger and drivers side, that had a black handle that you pulled towards the seats and what a difference it made, by letting the cool air in.

Same thing on my old VC Valiant. A vent system that really worked. No room to run that big duct up to the grill with modern vehicles.

[Ghosts]

Brissieboy I don`t mind the old Valiants and tis a shame they still don`t have that option these days.