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Air Con/Radiator Fans

C

CarlStewart

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Location
Warrington
Car
Accord
Had an aircon specialist out to look at my aircon - been putting it off - but with various issues with the car etc thought i'd get it done.

He checked for leaks and ruled that out - checked power to the compressor and nothing.
He messed around with a few things - he heard the click when applying power directly. But nothing when working as part of the cars electrical system.
He seems to think that the first place to look would be the aircon/fan relay - he said that the radiator fans should have been on and it wasn't. He showed me the red/high guage rising, so suggested I leave it disconnected until I get it sorted as it could make something go pop if left.

I have looked at the fuses/relays and there are loads that seem to be aircon related - does anyone know which ones would be repsonsible for the aircon AND fan??

Cheers
Carl
 
I know the part number for the relay is PFKL571878, but there are potentially 5 of these that are both aircon/fan related (according to my owners manual) - Joe public price is £21.24 per relay - so I'm not going to swap them all in one fail swoop.


I'm going to unplug all aircon related connectors etc (as per other threads) and see if this highlights and bad/dirty connections.


Then I'll test relays (is there an easy way to do this)??


Cheers
Carl
 
I ***ume he tested the pressure switch to make sure it works? Did you see him short the wires out on it? I would check the connector to it and the wires as that was the problem on my truck the wires had rotted a quick bit of soldering and a new plug and I have a/c again.
 
do your fans come on at all? say if you leave the car idling for a few minutes or 10?...maybe it is a relay but i would have thought a specialist would have been able to give that advice? or was it just a quick visit?
 
he was a mobile aircon guy, i'm having a fiddle tomorrow morning - changing alternator, and looking at this! - so I'll do more tests and report back. Cheers
 
Thanks CJ - I'll check on these in the morning when I change my alternator.

Tomorrow could be a big day for my car - it will determine our future together (if there is one that is!!).

Can't complain though really - almost done 200k in it and had very little go wrong (until now! - Aircon and Alternator).

Cheers
Carl
 
I know!! As much as I love it, I hate it at the moment!! If you know what I mean!

At the min my main issues are just the aircon and alternator, but knowing my luck I'll change the alty and the noise will still be there!!

If I can get to December with it, when mot is due and get it thru that, can either flog it or flog it to death (run it into the ground!!). But can't see me getting much for it anyway!!
 
Well - Alty change went well (around 1.5 hrs thanks to SAL's DIY). No rattling noise -YIPPEEE! (for now anyway!)

Whilst I was was in there disconnected and reconnected all aircon related connectors and checked wiring etc, but still nothing - no fans when a/c is on, and no change to idle when i turn it on either.

I take it I need to test the A/C clutch and pressure switch? I have (one at a time) swapped the 4 or so Denso relays under the hood, to no avail!

I have also left the car running for 10-15 mins and no fans kick in.

Any ideas boys?

Cheers
Carl
 
Can someone advise which connector I should be bypassing to test pressure sensor?? Is it left or right?? Left has 3 pins.

photo.jpg


Cheers
 
Have a read of this thread http://typeaccord.co.uk/forum/topic/4797-air-conditioning-not-working/ it could be a bad connection on one of those plugs from what Kow says in reply #9 the 3 pin plug has something to do with the fans.
 
This is doing my nut in now! Checked all connections - all are ok - I've cleaned them all and all seems well, but still no AC.

Can someone clarify - for me to power the compressor directly - all I need to do is run a wire from (red) + battery direct to compressor????

Cheers
Carl
 
Yeah I believe that's what u need to do but without the fans working you will run into problems.
 
Thanks for the reply Dave - I take it without the fans the high pressure would just keep rising? and something would go pop!??

Looks like I need to do a full check of the fan cables etc - oh what fun I'm having with the car at the moment!!!
 
Yes mate as far as I know it'll break something or blow gas out from somewhere. Its got to be something electrical have you got a multimeter? You could check if there is any power at all going to the compressor or if there is power going to the wires in the switch in the radiator. If you can't suss it maybe its time for a decent auto electrician to have a look he can check for power going to the relay and so on. Personally it'd drive me round the bend it not working and I'd have to know why.
 
Hi Dave - yeah that was my next port of call (the multimeter!!), ill try and get it done during the week if not then deffo the weekend.

Here's hoping for cool days (so i don't need the aircon!)

I'll document what happens and hopefully you and others can shed some light!

Cheers again.
Carl
 
hi all!
Still no joy with this! Checked all lower wiring etc and still no joy??

If I took to honda would they charge to put a code reader on ?? and would this tell me what the issue is?? (Fans still not coming on - I shorted a few of the wires in the 3 pin plug, and they came on for a bout a second and then stopped again (this was shorting the 1st two connnectors).

My compressor is working, (works with power applied directly) just the fans don't come on!!!
 
Doubt it would show up on a reader bud. Strange that the fans stop even with the power supply jerry-rigged.

Do they stop, but remain free to spin by hand? If not then they could be seized. Is there a faint hum coming from their motors?

Might be worth removing them and setting them up on a proper test rig (fused 12V supply).
 
It is terminal number 2 that needs 12V, terminal one goes to ground.
 
Have you tested the fan control relays?
 
They spin by hand ok Dan , and when I short 1 and 2 in the connector they come on for a second then go off with a bit of a humming noise? I have swapped around several of the denso relays and nothing has changed (so I'm ***uming the relays are OK).

Any other ideas pal?
 
Have you tried shorting pins 1 and 2 on the high speed switch? If the fan runs, its that switch.

If the fan stays off see if there is voltage between terminal 2 and ground.

If yes then there is a bad grounding. If no then you have a broken connection somewhere between the switch and relay box.

Are we talking Saloon or Tourer here BTW?


Scratch that - talking out of my hat - High speed sensor is just for the radiator...


Shorting terminal 2 of your condensor fan should bring it on totally...
 
The AC condenser fan relay is a 4 pin one... is there 12V on socket 1 to ground?

If yes, jump terminals 1 and 2.. and see if the fan runs. If not....we'll keep trying...
 
I had a similar issue recently when I swapped the headunit on my Accord for an aftermarket unit.. it basically stopped the fans kicking in and caused the compressor to discharge all the gas.. It was only when I took it to Hepworth Honda did we realise that the headunit swap had caused this.

Basically the stock headunit has the climate/ac control circuitry built inside and also controls the cooling fans. The techy did mention that he'd seen a few failing units now and it was always the headunit, not the relays. A long shot I know but if you can get a donor headunit for an hour, try swapping it over and see if it cures your problems. Are the fans not kicking in whether the AC is on or off?
 
No fans whatsover - even if I leave the car running idle for a while.

I have shorted pins 1 and 2 on the connector (3 pin) as per my earlier pic.

It's a saloon, by the way!
 
That wasn't the 4 pin relay though...

You need 12V to terminal 1 and ground, terminal 3 and ground, if not then it is a dodgy connection/fuse. If yes then there is a relay problem, diode problem, fan motor problem, or as Faddy said, a problem with the head unit.

Need to work through it methodically is all.

Terminal one of the fan motor goes to ground (via fan control relay) and terminal 2 receives 12v via the AC condenser relay. There is a diode in there somewhere which I presume stops the FCR bringing on the radiator fan with the AC.
 
Just to add a bit more confusion, since the weather has got hotter and mainly in traffic when the a/c fan cuts in the radiator cooling fan has also been kicking in at the same time on mine. Its actually considerably louder when both fans are going and I could hear it over the radio. As soon as I turned the a/c off it went quiet and then when I turned it back on again you could hear both fans kick in. I also noticed this yesterday whilst waiting for the cooling fan to kick in after doing a coolant change which after about 30 mins it hadnt done which is then when I turned the heating from hi back down to its usual 20 setting and as soon as it went from Hi the compressor kicked and both fans came on.....
 
:lol: Stick with it dude ;).
 
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