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Topic: air con (Read 1999 times) |
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november_man
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greetings chaps, I have just acquired a friend's 1996 Ultima. it has a few problems but the one that is causing me some head scratching is the air con. it has just been recharged and checked out. correct amount of refrigerant, pressure ok, no leaks . according to the site both fans should run when AC is in circuit. however, when stationary,only the offside fan trips in and out , running fast. do both fans come on to control engine temp. ? bit awkward to see what is happening when mobile though ! I have proved that the nearside fan is ok and there are no blown fuses.all the wiring, plugs and sockets appear ok. I have checked the big green relay. what is strange is that there is no indication on the contacts of the coils that the thing as ever worked. if this is correct then the " brain" has never talked to it with the correct language. could it be that the command parameters are not correct ? are the command parameters switchable in the programme ? anybody in the Manchester area I can talk to ? any assistance will be greatly appreciated.
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Geoff_W
Senior Member
98 Ulti2.5tdi Auto
Posts: 1340
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Re: air con
« Reply #1 on: Jun 6th, 2009, 4:47pm » |
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From your description it appears you are having difficulty with your aircon. Is this about temperature of air, volume, or is your ventilation system inoperative?
You have a 96 Ultima so I guess you have climate control, have you interrogated it for faults?
Have a look here > http://www.fordscorpio.co.uk/aircon.htm for an overview
and here to interrogate faults > http://www.fordscorpio.co.uk/ccreset.htm
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The winding road goes on and on... or at least it does in Northumberland
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Tompion
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1997 2.3 Ultima estate.
Posts: 2918
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Re: air con
« Reply #2 on: Jun 6th, 2009, 8:31pm » |
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This won't show up on the CC error codes.
Were both working before the work, or have you only just realised only one fan works?
It should be both fans on slow or both on fast, not just one fan.
It isn’t a programmable problem.
I have a feeling there were a few that were wired wrongly. Not sure if I read that on here or the mailing list. I’ll have a look through the emails later (not on this computer) if no one else comes up with anything.
Dave
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ABS multiplug wheel sensor pins MK IV or MK 20
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november_man
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Re: air con
« Reply #3 on: Jun 7th, 2009, 8:06pm » |
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thank you for the replies. ran engine in closed garage with air con on. when engine goes above normal operating temperature the nearside fan comes on to cool the engine down. it looks like one fan is used for air con and one for engine temp. could it be that this example is one of the rogue ones ? 
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Tompion
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1997 2.3 Ultima estate.
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Re: air con
« Reply #4 on: Jun 7th, 2009, 8:32pm » |
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I couldn’t find the thread I was thinking of, but I’ve come to the conclusion the little grey cells let me down & it was a different problem (think it was someone had a fan running backwards).
Anyway found a few emails I’ll post later that may be of use.
The green relay should connect the fans in series for slow speed & parallel for high speed.
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Tompion
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1997 2.3 Ultima estate.
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Re: air con
« Reply #5 on: Jun 7th, 2009, 9:08pm » |
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Found a couple of questions and answers, hope it makes sense, haven't checked it much - I assume the pinouts are correct. There's a link from Steve Collister to a diagram with some details of the relay.
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I have tried to follow the cooling fan circuit as given on the main site but not being that clever with electrical circuits I get lost when it comes to understanding whats happening,especially when a couple of diodes are thrown in and there are not the expected 2 relays but 3
Any electrical experts out there care to post a description?
What I can see is that there are 2 control lines from the pcm which fairly obviously get switched low to provide an earth path for the relay solenoids-problem is which is which (High/low)?
What is the purpose of the third relay and the diodes?
Eddie
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Eddie the drawing does show 3 relays but 2 of them actually come on together.
This is just to use another set of switching contacts.
The 2 relays may well be really one that has 2 sets of contacts.
Steve
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Have replied to eddie off list with circuit diagram and explanation.
If any one else would like to see it, I have posted it here.
http://www.collisters.plus.com/fan.doc
Steve
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The relay is designed to switch the fans in series for slow operation, or parallel for fast operation. The diodes are known as flywheel or back emf diodes. When the fans are switched off the magnetic field within the motor winding collapses, inducing a rather large voltage in opposing polarity, this can reach several hundred volts. The diodes shunt this potentially destructive voltage.
So with pin 17 switched on from the PCM, this causes the left & right relay coils to energise and the fans are in parallel and hence run at full speed.
When the other pin from the PCM turns on (pin 17 also turned off) the centre coil energises causing the fans to be connected in series, the effect is to half the electrical power, as the combined resistance is double.
Jamie
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A little time ago my fans (both little and large) were working intermittently I saw some info on the list about the relay on the drivers side behind the headlight, sometimes getting wet and this relay worked the fans. I played around with this relay and then I moved it and cable tied it up away from any where it might get wet. This seemed to work, till now. My fans have now stopped working with the Climate control (I don't know if they come on when car gets really hot as weather not warm and not gone anywhere except work, but they didn't before when I had the intermittent fault))
So my question is, have I got the correct relay, is there another relay I can check and what fuses control these fans, as I don't really want to check every fuse! I have tried playing with various wires and plugs around the fans in case it was a faulty wire but still no fans. Anyone got any suggestions I would be grateful.
Steviegee
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You got it right, that's the fan relay. It's long, green coloured, located right behind the right hand headlight.
Fuse no. 37 controls the first fan when it runs on high speed.
Fuse no. 39 controls both fans when they run on low speed.
Fuse no. 44 controls the second fan then it runs on high speed.
The fans should work as follows:
1. Engine cold, A/C off: both fans off
2. Engine cold, A/C on: both fans running on low speed
3. Engine hot, regardless of A/C: both fans running on high speed
4. Engine not running: both fans off (Scorpio is not like other cars, where the fans continue to run for a couple of minutes after shutting off the engine).
First, check fuses no. 37, 39 and 44.
Then remove the relay and take a look at the multiplug. You'll see that every hole has a number printed next to it. Take a piece of wire, turn on the ignition, and connect:
1. Hole number 2 of the multiplug to the ground (any suitable place on the engine, for example the octopus). The first fan (on your left) should start spinning on high speed.
2. Hole number 5 to the 12V supply (the + terminal of the battery). The second fan should start spinning on high speed.
3. Hole number 2 to hole number 5. Both fans should start spinning on low speed.
Please do the above test and tell us if the fans react as they should.
Vlad
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for Vlad,
I know this was not addressed to me but I have a similar symptom - only n/s fan working and only at high speed. so I followed your diagnostics as the relay is pretty new.
fuses OK
hole 2 to ground - nothing
hole 5 to +12v - ns fan runs high speed
short 2 to 5 - nothing
Does this sounds like an open circuit o/s fan or can there be another cause? I guess I should get the 2 pin fan connector apart and test continuity but I have failed the (where is the clip holding this connector together ) test set by Ford so far. The fan is free moving
Malcolm
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I had exactly this problem and it was a bad connector between the two fans, so check that out, it is a the offside back of offside fan and by the headlamp.
Mike
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november_man
Junior Member
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Re: air con
« Reply #6 on: Jun 8th, 2009, 4:13pm » |
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thank you for pointers. however, gone through the testing bit with regard the relay and had the same result as our colleague Malcolm. as regards Mike's comment about " a bad connector between the two fans" I can only find the individual fan connectors , the wiring for both of them meeting at the relay. I suppose the fans run the way they are told to do by " electronic big brother" !
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Tompion
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1997 2.3 Ultima estate.
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Re: air con
« Reply #7 on: Jun 8th, 2009, 7:21pm » |
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No, the ECU can't do that, it commands the relay to connect the fans one of two ways, series or parallel it can't command 1 fan only.
The fault is with the wiring relay fuses etc.
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november_man
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Re: air con
« Reply #8 on: Jun 9th, 2009, 1:27am » |
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let us have a brief resume :
all the fuses are ok, the immediate wiring is ok, the fans themselves are ok, that leaves the relay. will obtain a new one and see what transpires.
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Tompion
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1997 2.3 Ultima estate.
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Re: air con
« Reply #9 on: Jun 9th, 2009, 3:29pm » |
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Sounds like the relay may be the culprit – or one of the pins, see below. I’ve not looked at one of these, is it not possible to work out which contacts need to be made to connect pins no 2 & 5 & see if they energise when the aircon cuts in or can they be worked by hand.
Had another look through the posts but there doesn’t appear to be mention of an outcome.
Found a couple of other posts, but once again no outcome.
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Walther Sonne had a similar problem recently, traced I think to a bad connection at the relay (after he bought an expensive new one!)
Mark
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Malcolm,
Locate the plug of the fan that's not working (it's somewhere behind the fan, not far from it) and unplug the fan.
First, let's check the segment between the plug and the fan.
Using two wires, put 12 V across the two pins towards the fan (sorry, I can't remember exactly which side has pins and which one has holes, but I'm talking about the side that goes to the fan). The fan should start at high speed.
If the fan doesn't start, the problem is somewhere between the plug and the fan. Maybe even the fan itself.
If the fan starts, then we'll have to move on to the other side of the plug. It has two pins (or holes, I can't remember exactly). One of them must carry 12V and the other one must come from hole no. 2 of the relay multiplug. If you have a multimeter, you can identify them by measuring voltage between each of them and the ground.
You have to find a pin that delivers 12V.
If you find it, then connect the multimeter between the other one and hole no. 2 of the relay multiplug and see if you have zero resistance between them.
Vlad
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Hi, guys.
I found the cause of the non-working fan: it's the fan relay multiplug. Yesterday it started overheating again. I pulled over, left the engine running and lifted the hood. As expected, only the first fan was running on high speed, the second one was off. I removed the relay and used a piece of wire to connect the hole no. 5 of the multiplug to the 12V supply. The second fan started immediately. I put the relay back. The first fan started on high speed, but the second fan didn't move at all.
The relay is definitely OK, because it's new.
Fuse no. 44 is OK, too. I checked that.
So, the culprit must be the relay's multiplug. Pin no. 5 of the relay makes a poor contact inside the multiplug.
Vlad
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november_man
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Re: air con
« Reply #11 on: Jun 10th, 2009, 6:36pm » |
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greetings scorpio man, have attempted to open your info. on multiply site but it just appears as random code. have fitted replacement fan relay but it did not do the trick as suspected. I have checked the continuity of the wiring from the multi plug to the fans , no breaks. I wonder if the Ford Motor Company made a change to the wiring setup of certain Scorpio's ?
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november_man
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Re: air con
« Reply #12 on: Jun 10th, 2009, 6:51pm » |
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ps I can open up your water pump file which is pdf.
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scorpio_man
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Ford Kuga awd
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Re: air con
« Reply #13 on: Jun 10th, 2009, 6:55pm » |
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on Jun 10th, 2009, 6:36pm, november_man wrote:| greetings scorpio man, have attempted to open your info. on multiply site but it just appears as random code. have fitted replacement fan relay but it did not do the trick as suspected. I have checked the continuity of the wiring from the multi plug to the fans , no breaks. I wonder if the Ford Motor Company made a change to the wiring setup of certain Scorpio's ? |
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hi there
it's a word 2007 doc. i'll change it to pdf, when i get a minute.
hth
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scorpio_man
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Ford Kuga awd
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Re: air con
« Reply #14 on: Jun 10th, 2009, 7:01pm » |
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hi there
now sorted.
hth
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november_man
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Re: air con
« Reply #15 on: Jun 10th, 2009, 10:55pm » |
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top man
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november_man
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Re: air con
« Reply #16 on: Jun 13th, 2009, 12:10am » |
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to all contributors, coolant fans circuit now up and running correctly. the problem was no 12V supply from Fuse No. 44 to the 1st. fan. rather than a break in the loom, the notion was that a connector had come off the bottom of the fuse holder, but I fought shy of pulling the fuse box apart, could be opening Pandora's box ! I took the least line of resistance and spurred off a wire from connection / pin 3 of the relay ( soldered, hole sited on end of relay for wire to exit ) to the power feed of the fan motor using a scotchblock connector. a bit Heath-Robinson, but...............so, thanks to scorpio man,Tompion, et al
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