Xantia A/C

[admiral51]

Thanks Chris, Jim.

Went out this morning, fired the old girl up, and yes the fans are both working as they did yesterday.
Totally get what you are saying Chris, i was just hoping that maybe the use of the contact cleaner may have done some good, can always get another can
Jim if you have the time could you measure the length of the socket, just thinking of getting one adapted when i go back to work Monday. Was thinking of cutting it to a size where i could get a nut welded on top and be able to get a ratchet spanner on it. I have kept the box you sent the fans in so i can protect my knuckles from the A/C rad, them things are like a cheese grater.

Colin

[white exec]

Would a flat ratchet ring spanner get in there? Just a thought.

[admiral51]

Unfortunately not, the back of the casing is not flat it has a channel where the bolts sit.
Maybe able to use a cut in half ring spanner but not got any lying about to try, has to be cut in half otherwise the other end would dig into the A/C rad

Colin

[Rhothgar]

As the problem looks to be the cooling fans, the diagrams for those are as follows.
Looks to be the classic arrangement of 2 fans plus relays for the DW10...



As Kenny says, with IGN on, unplugging the Brown sensor usually brings fans on at full speed.
Turn them off by re-connecting the sensor, then turning IGN off then on.

Turning on AC should bring fans on at slow speed.

This is interesting Chris. My manual for my HDI is Page 97 for the same overview diagram. I wonder why yours is only Page 16? I doubt it is a diagnostics manual as they do not contain wiring diagrams that I've seen.

[white exec]

Probably from different publications. Most of the forum's Xantia circuits are from the Electrical Wiring Diagrams volumes.

[Rhothgar]

Probably from different publications. Most of the forum's Xantia circuits are from the Electrical Wiring Diagrams volumes.

I read through this long topic earlier today and am incredibly impressed with your input, Chris.

I've stripped mine this afternoon. The R/H fan (from driver's seat) spins but the L/H does not. The R/H fan without the fan on sounds like the bearings or bushings are on the way but the L/H fan is not stiff, does not spin up and does not make a sound when spun up manually.

Like a complete twerp, even after having read the post in full, I tried to remove the L/H fan as a right hand thread and having totally knackered the countersunk M4 x 12 x 0.7 screw which holds the fan into place.

Similar to Colin, I have had both free once I got the L/H one spinning and it continued to spin itself up after repeated connection and disconnection of the coolant plug.

However, on the initial spin up, I did notice that it was very lethargic in getting up to full speed. Is it really not possible to strip these down fully and get them back together with a pop riveter I wonder?

It would be lovely if I didn't have to spend any more just yet on the car.

Air con simply will not kick the fans in at all though. Maybe needs regassing. Have not tried the trick Colin refers to on a number of occasions because I've not looked into that yet. Nothing there though that would presumably stop the operation.

Unfortunately, I built it back up and went for a spin but the fans didn't come on until it was over 100 deg C so allowing for discrepancy in the dash that will be 105 deg C for sure as they were on full tilt. Well! One was.

Oh and Colin. Have you got a spare screw kicking around by any chance please? Otherwise £12 from China for more than I'll ever need...

[admiral51]

Just a quick update, with what i believe is some progress.
I have today taken the old girl out for a short run to the local shops and then the tip first time she has moved since i took my lump hammer to the motors
On previous attempts to fix the issues i had got them both running whilst stationary as they should but once driven they would stop, checked this at the time by making sure they were working before i left, when i stopped mid run they were not, and they would need a good flick with a screw driver to get them to spin again and they would have stopped by the time i got home.
Now today i tried a different approach, i drove with the blower off for a few short stop start journeys to different shops, and before i got to the last shop before the tip journey i turned the blower on and set it to demist. When i got there before switching off i checked to see if the fans were running, as per my gut feeling they were not
So next test on starting for the tip run, start engine turn blower on and set to demist, check to see if fans were running as they had been the last few days, no
So get the screwdriver out and see if a gentle flick would get them running, yes it did but a very gentle flick this time. Pretty much just the pressure from the screwdriver moving the fan no more than from 12 - 1 oclock had them both spinning. So off to the tip we went and whilst in the queue the temp gauge hovered around the 75 mark, normally it sits at 80 -90 max when in stop start traffic so are they running after being driven for 4 miles hell yes
So popped round to see my parents for an hour after the tip and the fans were running again after i started the engine from the tip.
On the way home i deliberately had the blower off when i started, it is only a 5 mile trip, and mid way home i put the blower on, set to the floor vents and then pressed the A/C button (A/C not gassed ) and when i got home the damn fans were running
Tomorrow i will go for another drive and then see if i can get the fans to cut in at the slow speed temperature.
I know it is not 100% fixed, i still believe one of the fans is suspect and i may just give them a both another dose of contact cleaner before i do the test and Monday when i go back to work i will have the chance to see if the fans will continue to run on a 35 mile run.
Until i either get enough cash to throw at someone to do the replacement swap or get the modified socket i will keep going with the current fans i have installed.

On a side note for those that are way more knowledgeable than myself i have a (silly/stupid)question
When the blades are removed not only do you get access to spray contact cleaner in to the motor windings area i also get access to the motor spindle where it exits the motor housing.
As Jim has stated the motors are not serviceable items in terms of taking them apart and refurbing them, so could i use a spray grease and attempt to use the very small gap between the spindle and the casing to put some fresh grease in to the workings ?

Colin

[admiral51]

Roger i have more than 1 spare screw and apart from the 2 fans i got from Jim i think i have 3 others, none of which i can yet confirm are working.
So you have the R/H fan working, that controls the L/H one when in slow speed as they run in series at slow speed. I assume you have the L/H one not working unless when stationary and/or given a helping hand. The fact that you have the R/H one running at fast speed when temp gets to the required level means the system is actually working. I would guess that the R/H fan is actually working on slow speed when the temp is reached just that you are not aware of it as on its own it is not sufficient to cool the system.
What settings did you have to get the fans to both run at slow speed, ie was the blower on and set to demist or did you have the blower on and the A/C button pressed AND set to demist ?
What the link is i do not know but even with a duff A/C setting to demist with the blower on should set the fans to slow speed, same with pressing the A/C button regardless of direction settings with the blower on.
I would check again the relays, well more to the point the sockets they fit into. From experience when you push the relay in there is a chance that the socket itself is pushed back out of its locating place. Whilst the relay is in place it may not be fully located. I noticed like me you broke the tabs off of the relay cover, easy fix is to go back to the MK1 system, get yourself 2 self tapping screws and use the blanking plugs on the cover to screw in to the lugs on the back of it

Colin

[white exec]

I'm beginning to lose the plots (2 of them!) here, which could be my fault, so apologies.
Two of you with ostensibly similar issues, but now piled into one thread, or sometimes split into more than two!


Right... Reset...

1. The individual 12v fans need examining and testing separately, without being connected to the car's system. Do they spin freely (i.e. not seized)? Do they start when 12v is applied? Do they rotate powerfully? Do they both perform the same? This has to be got right before any further progress can be made.

2. When connected up to the car's system, they should both run at slow speed when the AC is switched on. This has to be got right. This shows that the three relays can successfully connect the fans in series.

3. If all of the above functions properly, but driving (or a park-up warm-up) only brings on one fan, then this indicates that slow speed is NOT being properly triggered by the temp sensor and ECU, but that evrything is waiting for high temperature to be detected, and the fans to operate Fast and in parallel. If one fan is dud (which should have shown up by turning on the AC), or the relays are at fault, then IT IS POSSIBLE that fast speed will only be seen on one fan, not both. (Just like having two light bulbs in parallel, one good, one blown.)

4. The relays may need checking or renewing. Remember that one of them is 5-pin (a changeover relay) and the other two likely 4-pin ('make' only). It's important to get the 5-pin felay in the right socket....the one with 5 lots of wiring to its base. Alternatively, just fit 5-pin versions to all three sockets, then correct positioning doesn't matter.

5. Slow speed running (fans in series) should be triggered by switching the AC on. Fast speed should happen if the connector to the (brown, iirc) temp sensor is pulled.

6. Relay and relay socket corrosion is a known problem on Xantia (and XM) where these items are mounted up-front, and prone to weathering. The relays have a hard life, handling anything up to 25A apiece, and double that on fan start-up. Internal contacts can become arc-damaged. Cheap enough to just replace anyway.

7. Motor brushes and commutator issues have already been discussed.

And that is it.
Beyond that, your're into WTCU (water temp control unit) or ECU (AC ECU) failure, and the need to get a good auto electrician on to the system.

[Rhothgar]

I'm beginning to lose the plots (2 of them!) here, which could be my fault, so apologies.
Two of you with ostensibly similar issues, but now piled into one thread, or sometimes split into more than two!


Right... Reset...

1. The individual 12v fans need examining and testing separately, without being connected to the car's system. Do they spin freely (i.e. not seized)? Do they start when 12v is applied? Do they rotate powerfully? Do they both perform the same? This has to be got right before any further progress can be made.

2. When connected up to the car's system, they should both run at slow speed when the AC is switched on. This has to be got right. This shows that the three relays can successfully connect the fans in series.

3. If all of the above functions properly, but driving (or a park-up warm-up) only brings on one fan, then this indicates that slow speed is NOT being properly triggered by the temp sensor and ECU, but that evrything is waiting for high temperature to be detected, and the fans to operate Fast and in parallel. If one fan is dud (which should have shown up by turning on the AC), or the relays are at fault, then IT IS POSSIBLE that fast speed will only be seen on one fan, not both. (Just like having two light bulbs in parallel, one good, one blown.)

4. The relays may need checking or renewing. Remember that one of them is 5-pin (a changeover relay) and the other two likely 4-pin ('make' only). It's important to get the 5-pin felay in the right socket....the one with 5 lots of wiring to its base. Alternatively, just fit 5-pin versions to all three sockets, then correct positioning doesn't matter.

5. Slow speed running (fans in series) should be triggered by switching the AC on. Fast speed should happen if the connector to the (brown, iirc) temp sensor is pulled.

6. Relay and relay socket corrosion is a known problem on Xantia (and XM) where these items are mounted up-front, and prone to weathering. The relays have a hard life, handling anything up to 25A apiece, and double that on fan start-up. Internal contacts can become arc-damaged. Cheap enough to just replace anyway.

And that is it.
Beyond that, your're into WTCU (water temp control unit) or ECU (AC ECU) failure, and the need to get a good auto electrician on to the system.

Apologies for bombing the thread. I shall duly stand down for now.

Colin. I will answer your questions separately.

Some very good clear points there again Chris. I'm fine with some diagnostic things. I have checked all my relays and contacts and good. I did install a new one I had bought in the change-over relay position. On inserting one relay, pushing and pulling the relay with connector backwards and forwards as it had come off its clip caused an intermittent fault. That was maybe the relay as I swapped them all around until it stopped even with waggling!

It's almost, if not, impossible to strip those connectors down in situ because there is not enough slack. I did note that there are two very thin brown wires behind the relay. I've not checked but I am guessing they could be the signal wires from the ECU.

[white exec]

The thinner wires will be the signal (relay coil) connections, one grounded, the other to the ECU.

[admiral51]

@Admins
Could we maybe move the posts not directly to my original thread into Rogers Xantia Dash Light thread where i have replied about his fan issues so we keep them tidied up and at the same time allow everyone to see them as although the issues are similar the fix maybe totally different and there is a link in Rogers post to this thread.

Colin

[Rhothgar]

The thinner wires will be the signal (relay coil) connections, one grounded, the other to the ECU.

There appears to be an anomaly in the wiring loom diagram which would be page 17 in your manual.

Wire 1540 appears twice. There is a signal wire from ECU which becomes 8091 at IC62 which feeds 1504 Pin 2 with wire 157.

The Component Overview diagram (Page 16) shows a splice for these two wires but one doesn’t exist splicing 157/8091 together.

Pin 3 of the Change-Over Relay (1504) is also number 1540.

Maybe something. Maybe nothing.

Am I right in saying that when blue (not brown) coolant connector (1220) is disconnected it goes open circuit and ECU programming is such that it switches fans on once it sense this.

I can see temp sensor is earthed via engine earthing so what is the third wire coming off the plug? Something to do with air con circuit? And do you know if 1235/1236 are 5V? I assume they are being a sensor.

[Rhothgar]

@Admins
Could we maybe move the posts not directly to my original thread into Rogers Xantia Dash Light thread where i have replied about his fan issues so we keep them tidied up and at the same time allow everyone to see them as although the issues are similar the fix maybe totally different and there is a link in Rogers post to this thread.

Colin

Great idea. Sorry Colin. I’ve only just learned to use Bookmarks in all these years. Often wondered how people kept track of good threads.

This topic contains such great info from Chris that it ought to be a sticky.

[admiral51]

Ok i know its me and it is a Sunday night but just had a thought

I will be getting a couple of modified sockets made up over the coming week to see what works in relation to the limited space available to get the nut removed without the need to remove half the front of the car.
However, thinking about it logically we can check the feed to relays, check the relays, clean all the contacts but the one thing we cannot do unless we remove the motor itself is check the contacts that connect to the motor. The reason being is they are what i class a push fit, the plug itself is i think part of the motor housing, or at the very least something that is not serviceable whilst in situ. If as we know that the relay contacts themselves can burn out and or get dirty over time then is it reasonable to assume that the contacts on the motors themselves could suffer from the same issue?
By that i mean the wiring is clipped into the motor housing frame and in essence is a normal plug and receptor, the receptor is located in the motor assembly that can only fit in the frame in one position and whilst i have thought the fans themselves were/are knackered need of repair/replacement is it possible the one part of the system i cannot get to easily to clean could be playing a big part in the issues i and others have had over many years.

Like i said just idle thoughts and i will be investigating over the coming weeks


*******EDIT*******
Had another thought, and all the above is based as a DIY mechanic, if i have gone and done all the fault finding and cleaning of contacts/relays then i would by nature clean the contacts before fitting the new motor, and if it worked all is good, but just by removing the old motor i would have taken some crud out, be honest if you fit a new component and it works who would take the new one out and try the old one again. Yes i know there are some that would but less than 15% i guess
Colin