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Topic: CC HIGH PRESSURE PROBLEM._ 1998/2.3 (Read 798 times) |
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surfcoast4
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CC HIGH PRESSURE PROBLEM._ 1998/2.3
« on: Jun 15th, 2006, 12:04pm » |
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Hi guy's process of elimination and reading of the forum has led to thus so far- Fans continually running when A/C is on, re-gas and all other checks reveal nothing hence we have a blockage- seems the high pressure pipe inner casing may be split or something of the like, going in for a new pipe Monday But- airflow thru the cabin vents appears to deminsh when the fans are running...my question is of course ,are the 2 problems related and will the later be resolved once the H/P pipe is replaced? as usual your kind thoughts would be much appreciated....Andy 
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scorpio_man
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Ford Kuga awd
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #1 on: Jun 15th, 2006, 1:33pm » |
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hi there
who's telling you all this? an air con tech? did they put the system in to a deep vac for at least 20mins?
why the pipe? does the pipe to the evap get cold/wet?
didn't anything show on the gauges? should've done!
re lack of air flow. have you checked the pollen filters? what sort of vent temp are you getting? maybe the evap is frozen.
can you give us a bit more info. when did this problem start.... before or after the regas, etc.
hth
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surfcoast4
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #2 on: Jun 15th, 2006, 2:09pm » |
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HI Andrew,
Thanks for your reply, firstly, checked the pollen filters recently, not very old, gave them a clean anyway while they were out, no probs there at this stage.
Vent temp going down to 4.5 at the moment...had several re-gases in the last 2 months trying to resolve this problem.Including reducing gas load from 1000 down to 750 ish to try and reduce the pressure...fans still running.
Problem started prior to any re-gasing and prior to any hot weather infact it first started in winter under normal CC running.
If CC is turned off and we run on normal ventalation the fans dont run and inside airflow thru the vents returns to normal.
Gauges all showing normal running/no over heating etc.
Must admitt I havent checked evap pipe myself recently.
Thanks again
Andy
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sector-9
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #3 on: Jun 15th, 2006, 6:15pm » |
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I discovered that with CC turned on in my diesel the engine fans would run on high all the time - even if the a/c compressor was unplugged!
I don't believe this is supposed to happen, but looking at the wiring diagram I can see why it does. I've since made a small modification to the loom near the pressure switch and now the fans only run when a/c pressure builds up (and usually only for a few seconds). The trinary pressure switch is actually two separate switches in one physical unit. One of the internal switches shuts off the compressor if pressure is too high or low, and the other brings on the fans at a certain pressure (which is lower than that needed to turn the compressor off).
If airflow is being restricted from the vents (does the blower fan slow down?), then it could be the evaporator freezing up which will obstruct the air inlet - you may be able to see this with the bonnet up and pollen filters removed.
Darren
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David_South_West
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #4 on: Jun 16th, 2006, 9:47pm » |
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Sector9....I have similar problem with fans....what modification to the wiring at the switch did you make?
Thanks
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sector-9
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #5 on: Jun 16th, 2006, 11:38pm » |
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I disconnected the black ground wire from the trinary switch, and in it's place connected the wire which is grounded when a/c on (which I disconnected from the fan switch wiring). I can't remember the wire colours from memory but looking at the PDF I think it is black/orange causing the trouble - this is grounded by the HBC relay but because it is also connected to the fan switch it causes the fans to run whenever the a/c is turned on.
If you look at the PDF wiring diagram, 34-04-008, it is 31S CA 13 and 31S CA 38 I have cut and joined together - however it is possible that the problem may just be caused by the diode C948 being connected the wrong way around!
Darren
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surfcoast4
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #6 on: Jun 19th, 2006, 11:23am » |
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Thanks again Darren & Andrew for your assistance, took a trip away to the Polish Scorp meeting this weekend, great weekend had by all, and had a chance to check a couple of things, namely that yes the Evap is freezing up, and the pollun filters were dirty again.
Interesting about the fan wiring Darren, will look at that option too, not sure whether to replace the H/P pipe still or not, the system was put into deep vacum for well over 20 mins.
Andy.
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hellblue
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Ill have silver,it dries just as fast !
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #7 on: Jun 19th, 2006, 10:30pm » |
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both fans sould run on slow when ac is on,the system may pass a vacuum test with a faulty o ring/seal as the vacuum can pull it in and seal it, system should be recharged and a dye added and uv checked for leaks around pipework and connections etc .i have sometimes known the hi press. pipe valve not to open with the gas machine connection a blockage! try regas via low press. connection Gary
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Gary
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sector-9
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #8 on: Jun 19th, 2006, 10:40pm » |
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At Harewood meet yesterday we compared a few cars and there seemed to be about three combinations for how the fans run!
On my diesel, the cooling fans would run on high speed all the time A/C is turned on. On Mazzy_J's diesel and Richard's Cossie they would run on low speed all the time A/C on. On Snoopy's 2.9 12V they ran (on low speed) only when A/C pressure builds up.
I've changed the wiring on mine so now they run on high speed only when A/C pressure builds up (but I may change it so it runs on low speed instead like Snoopys does).
Take your pick which one you think it should be - Ford obviously changed it a few times - I've set mine how I think it should be done and it works fine but I'm no A/C expert...
Darren
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Snoopy
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #9 on: Jun 20th, 2006, 8:04am » |
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Darren You have it wrong ...... MY 12v run at HIGH speed when pressure builds up then switch off ( Like yours doeas now, i.e. cycles ) and Richards 24v run ALL the time when the A/C is on at LOW SPEED.
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surfcoast4
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #10 on: Jun 20th, 2006, 10:26am » |
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Thanks all again, still bemused by it all...seems we have 3 or 4 different wiring options for the fans, so assuming the wiring in this instance is correct, ie..always only came on when there was a pressure build up and ran on high and then cut out....eliminates wiring and suggests there is definately a blockage.
Evap freezing up and pipe getting wet...
All other tests proved negative, dye's , deep vacum tests, no leaks ,not loosing gas, re-charged and re-tested several times!!!!!!!!where too now?
Andy
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sector-9
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #11 on: Jun 20th, 2006, 5:24pm » |
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Having looked at the wiring diagram I don't think it's a wiring issue on the EEC-V equipped cars - there is no direct connection between the air con system and the fan circuit. As the fans are switched solely by the ECU I suspect that the only way to change their mode of operation is by changing the firmware in the module. In short though, don't worry about it - it's possible that the ECU only makes the fans run when the car is below a certain speed (anybody care to confirm this theory?)
Darren
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Snoopy
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #12 on: Jun 21st, 2006, 7:39am » |
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If the evap is freezing up doesn't that mean that the compressor is NOT disengaging to allow a defrost. if so that is where you problem is . the compressor should disengage to allow the system to de ice.
Well mine does .
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sector-9
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #13 on: Jun 21st, 2006, 12:00pm » |
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Wonder if this car has had the mod done mentioned on the site. In normal usage it shouldn't ice up as the de-ice thermistor is very conservative and should stop the compressor long before it begins to ice. OTOH, if the mod has been fitted then it may be turned down too low, or the thermistor may have broken or moved away from the evaporator coils.
Darren
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surfcoast4
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #14 on: Jun 21st, 2006, 12:24pm » |
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Truely amazing Darren, just finished reading about the A/C mod...lol and NO it hasn't YET!!but worth thinking about it.
Andy.
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Daven
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #15 on: Jun 21st, 2006, 2:23pm » |
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Has the expansion valve been checked? I had similar problem - system was under constant high pressure and the fans came on even if I had turned the AC off as I turned on the blowers!
The A/C clutch wouldn't disingage either!
The valve was effectively breathing in but not out!
Dave
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surfcoast4
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #16 on: Jun 25th, 2006, 10:40am » |
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Up-date time guy's thanks for your comments so far.
Decided against replacing H/P pipe and replaced the dryer unit - again!! was replaced 2 years ago.
Problem solved....for about an hour  .
So here's what we have:- new dryer unit, new pollun filters, complete re-gas and withdraw and re-gas pulling out all the old oil etc, deep vacum twice,NO leaks. oh this was all last thursday by the way, situation now;- fans cutting in and out as required- complete ice up of the top hose(low Pressure).. if we take the interior fan control from auto and manually adjust the fan to HIgh...it de-ice's the pipe and evap .....conclusion!!!
De-ice switch  ??
cheers
Andy
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scorpio_man
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #17 on: Jun 25th, 2006, 12:01pm » |
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hi there
i had to replace my de-ice switch as it was reading too high and the system kept running to try and cool it down.
first check that it's in the correct position and then check it's working.... http://www.fordscorpio.co.uk/deicetest.htm
not sure if you can tell if it knows the correct temp or not. 
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surfcoast4
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Re: CC HIGH PRESSURE PROBLEM._ 1998/2.3
« Reply #18 on: Jun 26th, 2006, 8:41am » |
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Thanks Daven, thought about that too but that was replaced in January, although it could be faulty I suppose.....cars!!!!!!!!!!
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