Is AU aircon affected by thermo fans?

[ronwest]

The aircon (climate control) has been playing up lately.

Sometimes it's cold, sometimes it's not.

I took it to aircon guy this morning and he can't fault it.

What he did say is that if the low speed of the thermo fans only is working (ie no high speed) it would affect the aircon - build up of head pressure, (or words to that effect).

The car hasn't been getting hot - temp gauge sits where it always does.

So, any aircon guru's can confirm what he's saying?

[BHDOGS]

easy enough to test if the thermofans work when the aircons on

[ronwest]

Originally Posted by BHDOGS

easy enough to test if the thermofans work when the aircons on

Thermo fans definitely work but he's saying they are only working on "low" speed"

I think that what he's saying is that there's a problem because the "high" speed fans aren't working?

There's no variation on temp gauge at any time - city driving, highway driving etc.

I guess I could supply power to the high speed side of the fans but I figure that if there's a problem it will be on the control side rather than the fans themselves.

So I guess two questions:-
1. Will high speed thermos not working affect aircon?

If yes,

2. What controls the fans?

[Maka]

Ron, to test high speed fans turn your aircon & fan blower to flat out or pull off the connecter to the temp sensor on the back of the head & see if the high speed setting works.

1) yes, on a really hot day your motor might overheat if the high speed fan setting is not working

2) the thermo fan relays are in the under bonnet fuse box (2 black & 1 green relay) & the aircon relay is located in the cabin fuse box, its a green relay. Maybe swap the relays around to confirm if there is a issue there.

cheers, Maka

[ronwest]

Originally Posted by Maka

Ron, to test high speed fans turn your aircon & fan blower to flat out or pull off the connecter to the temp sensor on the back of the head & see if the high speed setting works.

1) yes, on a really hot day your motor might overheat if the high speed fan setting is not working

2) the thermo fan relays are in the under bonnet fuse box (2 black & 1 green relay) & the aircon relay is located in the cabin fuse box, its a green relay. Maybe swap the relays around to confirm if there is a issue there.

cheers, Maka

Thanks Maka. Precisely the info I was after.

Cheers...

[philfree]

hi i can answer yes i often hear my fans switch from low to high they are a bit noisey and being a auto electrision who also does ac i can confirm it's because of the ac needing the extra air flow with the ac off they fans barely even switch onto low speed. also their is 2 or 3 relays for the fans i can't rember where their are i think they are in the underbonnet fuse \ relay box if their are not their they are infront of the passanger side headlight i would check those relays out as normaly one of those are the problem just use caution because they maynot be all the same you can check this by removing them and looking at the little numbers next to the pin to see if they match up eg 85 86 87 87a and 30 if they match they they will swap over hope this helps i can almost guarantee if their is a fault with high speed it will be in those relays

[ronwest]

Originally Posted by philfree

hi i can answer yes i often hear my fans switch from low to high they are a bit noisey and being a auto electrision who also does ac i can confirm it's because of the ac needing the extra air flow with the ac off they fans barely even switch onto low speed.

Thanks for confirmation. Appreciate it.

[mik]

Something else to check, and that is the heater tap, the heater can easily over power the aircon, if you have a slight vacuum leak, or weak vacuum supply to the heater tap it will stay in the default position open or on hot,
at times you may notice at different throttle openings the aircon will heat up then mysteriously cool when you get back in cruise throttle position, well worth checking the vacuum side of things.