Advice needed Re: Xantia Cooling fans (non air con)

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DaveW
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Advice needed Re: Xantia Cooling fans (non air con)

Post by DaveW »

I have a problem with the cooling fans on my Xantia (1.9TD Dimension - No Air Con).

Prior to my acquiring the car it had been involved in a minor off road excursion due to a patch of ice unnoticed by the young lady driver.
The resulting damage to the underside of the front bumper had pushed the top inner edge of the bumper up enough to make contact with the fans.
The L/H (viewed from the driving position) fan was jammed pretty tight - very difficult to turn by hand - the R/H less so but still not free spinning.
I have cleared both fans but, when shorting the radiator temp sensor socket, only the L/H fan runs.

A voltage check on the socket yields :
Between pins 1 & 2 --- 11.8 V. (dodgy battery ?)
Between pins 1 & 3 --- 2.8 V ... ????

I have checked all of the fuses (under dash) I have seen mentioned in other posts (but these seemed to be about air con equipped cars) and all are OK, all of the engine bay fuse box fuses are good.

What I find puzzling is the odd voltage on pins 1 & 3.
Anyone encountered a similar problem or can offer a possible solution ??

The three relays between the fans all energise when voltage is applied to their coils - good healthy sounding clicks - so if I can restore a 12 V supply to pins 1 & 3 I can then see if the R/H fan is good or not.


Is the L/H fan the 'low temp' one as if so I will at least have some cooling for normal motoring conditions. Anyone confirm this ??

Dave,
Xantia Forte 1.8i, 16v X reg.(09/2000) 93K, aircon
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Post by RichardW »

Both fans should run - either in series (low speed) at the first temp, or in parallel (high speed) at the second temp. I think! Not sure why you have slightly odd voltages, but you may need to short all 3 pins to get high speed - I'll need to check the wiring diagram. I think if the RH fan doesn't run then it's possible it's burnt out from being jammed. Can you connect the fans directly to the battery to see if they will run?
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Post by Clogzz »

Not sure about non-aircon models, but if it has 3 relays, I think that both fans always have to do the same thing: both stopped, both at low speed, both at high speed.
This BX thread may be of help:

http://www.bxclub.co.uk/forum/viewtopic.php?p=6857
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DaveW
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Post by DaveW »

Thanks Richard and Clogzz,

Between posting the question and reading your replies I had reasoned that both switches may need to be closed. I tried that but with the same result.
I can't see how to get a direct 12 V to the fan to test it without pulling the rad/intercooler. ?

Dave.
Last edited by DaveW on 04 May 2006, 15:06, edited 1 time in total.
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Post by Clogzz »

Don’t understand the relevance of voltages between the pins.
From what I do think, the sender switch has a permanent 12 Volts on pin 1.
Shorting pin 1 to pin 2 sends 12 V to one relay to operate the low speed on both fans.
Shorting pin 1 to both pins 2 & 3 energises all 3 relays to spin both fans at the high speed.
This map shows how the relays operate the fans, actually simpler because there’s the sender switch in place of the Bitron:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=17012

Close to midnight here, Image hope RichardW will be back. :D
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DaveW
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Post by DaveW »

As I said in the edit, all above was waffle. I've edited it out to avoid confusion for others.

Having pulled the relays again and checked that all of the contacts did close as they should, I tend to agree with Richard that the motor must be shot. The L/H fan seems to be running at quite a high speed.
I'll see if there is a way to get the R/H one out through the front.

Dave.
Xantia Forte 1.8i, 16v X reg.(09/2000) 93K, aircon
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Post by RichardW »

I am back...armed with the wiring diagram.

I wouldn't worry about the voltages at the pins - the switch is used to earth the relay coils (via pin 1), so measuring any voltages is pretty useless.

So... with the ignition off, shorting pins 1 and 3 on the rad switch connector should bring the fans on low. With the ignition now on, short pin 2 to 1 as well, and the fans should go to high. If nothing happens with 1-3 shorted, but one of the fans comes on with all 3 shorted, then the non runner is shot. If you short 1-2 only with the ignition on, one of the fans only should run at full speed. Unfortunately the diagram doesn't say which fan is which. However, the diagram for A/C cars indicates that it should be the RH fan which should run on its own with the 1-2 short with ign on.

I think.

There is a post somewhere by AlanS about taking out the fans and refurbing them. Not easy....!
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Post by DaveW »

I took the R/H fan out and connected to 12V it runs fine.
There is no sign of corrosion on the connector or plug and the meter shows that there is a good earth connection to one side of the connector.
With or without the ignition on, there is no voltage on the other side when the rad switch pins are shorted.
There is also an earth connection on pin 5 of the change over relay socket.
As I said earlier, all three relays appear to operate correctly and show continuous contact on the switched pins when the coil is energised directly from the battery.

I have checked fuses F2, F3, F7, F10 in the dash fuse box and re-checked all of the ones in the engine bay box.

At the moment I am stumped.
I have yet to check the connections inside the triangular relay box - I would doubt that these would be corroded, but you never know. Will have a look tomorrow.

Dave.
Xantia Forte 1.8i, 16v X reg.(09/2000) 93K, aircon
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Post by alan s »

Does sound a bit external in this instance, but if you decide to do them over while you have them out, here's the info.

http://www.frenchcarforum.co.uk/forum/v ... hp?t=10752

Worst part of the job is removing and refitting unless someone has already had them out and done couple of mods to simplify the process.
On air/con cars, they live a hell of a life, so I would expect their life expectancy on a non air/con car to be quite lengthy.


Alan S :wink:
RIP Sept 19th 2008.

She said "Put the cat out" She didn't mention it was on fire!!
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Post by DaveW »

Thanks Alan.
I had read your post before and it is very useful info. to know.
Both fan motors seem to work fine at the moment - just not together in situ !!

I have found a diagram in the BOL and will study it tonight. From a first look through, the most obvious thing would appear to be a relay but these all test OK.

The car is due for MOT on Monday so if I cannot sort it out by tomorrow night I will just have to put it back together for now. The MOT garage is only six miles away and it should get there OK without overheating.

Richard,

On my car it's the left hand fan that runs quite fast when pins 1 & 2 are shorted with the ignition on.

Dave.
Xantia Forte 1.8i, 16v X reg.(09/2000) 93K, aircon
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Post by RichardW »

Dave,

Looking at the wiring diagram there are some additional fuses - and there appears to be one for each fan. They're titled BMF1 and BMF2 - and Haynes tanslates this as "Max. - fuse box". If the one for the RH fan is cooked as it has been stalled, then you would be able to get the LH fan to run but only on high speed. No clue as to where these fuses are - except they're fed directly off the battery +ve. My handbook says there are some high amperage fuses in the underbonnet box, but doesn't say what they're for. I guess you need to check for a permanent +ve feed to pin 3 on both the 4 pin relays. The earth from pin 5 on the change over relay is correct - this is the earth for one of the fans when they're running fast.
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Post by DaveW »

Richard,

Yes, I too had noticed those fuses but where they are in the car is mystery at the moment,

According to the 'key' in Haynes, BF00 is the passenger compartment box, BB10 the 'supply box' (engine bay??) and BMF1, BMF2 the 'Max. -fuse box.

First thing tomorrow I will go through all the higher rated fuses in the main (cab) box. I am 100% certain that all of the engine bay fuses are OK as I checked each and every one by pulling them and putting the meter across. The big jobs, 60A etc. showed 12V on each side so those also are OK.

There has to be a logical solution other than the unlikely one of a discontinuous wire.
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Post by Clogzz »

Hi Dave,

If you’re handy at the search, citronut has an old post explaining how to remove the fans through the front, without taking the bumper out.
Don’t find it, and it could be a year old.
The fan blade retaining screw has a left-hand thread.
Picture showing possible location of two 40 Amps fan fuses in the red square.
The location depends on the model.
Best of luck !

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Post by DaveW »

Clogzz wrote:Hi Dave,

If you’re handy at the search, citronut has an old post explaining how to remove the fans through the front, without taking the bumper out.
Don’t find it, and it could be a year old.
The fan blade retaining screw has a left-hand thread.
Picture showing possible location of two 40 Amps fan fuses in the red square.
The location depends on the model.
Best of luck !
Thanks Clogzz.
I got the fan out by removing the air filter box, pulling off the intercooler rubber pipes, removing the top hose and tilting the rad. back a little, this allowed me to undo the nuts at the back of the fan mounting. It's a tight fit between the plastic top member and the intercooler even for my small hands and arms.
The fan can then be squeezed out through the front (with the grill removed).
Once out I could see that with the blades removed (discovered the left hand thread) it might be possible to undo/ replace the mounting nuts through the front. The motor is OK.

I have two chunky 40A fuses in the engine bay box but these check out OK as do all the others there (went through them with ohmmeter to double check this morning). I also checked every fuse over 15A in the 'passenger compartment' box.

I'm about to take the back off the (3)relay box to see if I can see what colour wires provide the +12V to them and then try to trace them (ever hopeful ! )
I just wish I had a sensible wiring diagram for the car that gave such information.
Fortunately it's only a short run to the battery/fuse box.

Have you ever removed an engine bay fuse box ?

Dave.
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Post by Clogzz »

Hi Dave,

You haven’t wasted any time this morning. :D
The Haynes maps never show wire colours, but always indicate the plug/socket colours.
At the low fan speed, they get 6 Volts each, perhaps not enough for a ‘marginal’ motor.
Recent story here, 3 pages:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=18871

Never removed an engine bay fuse box, and hope that I never will. :shock:
I’d rather spend hours measuring everything.
The pictures are not of my car.
I copied them from the French ‘Planète Citroën’ forum:

http://www.planete-citroen.com/forum/sh ... 530&page=3

Have a nice day on the job. :lol:
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