Gasa XM 2.1 "Prestige"

[Dieselman]

That's good to hear.
From the image it appears the two plates are seperating, which along with the front and rear jacking points is one of the first places for an Xm to rot.

[Gasa]

...at what degree do the radiator fans turn on, today it reached 90-95 degrees and the fan did not turn on.

[Gasa]

A work was done today, a major service was done, all engine mounts and alignments on the gearbox and engine were replaced, as well as the couplings, steering wheel cuffs, and the bearing on the half-shaft.

IMG_20230423_094751.jpg

IMG_20230423_125115.jpg

IMG_20230423_125138.jpg

...the lower bracket was in a very bad condition, the oil completely melted the rubber.

IMG_20230422_093937.jpg

IMG_20230422_093945.jpg

IMG_20230422_185851.jpg

..and the bearing on the shaft was replaced.

IMG_20230422_100623.jpg

...new and old engine mount.

IMG_20230423_150344.jpg

[DownUnderXM]

...at what degree do the radiator fans turn on, today it reached 90-95 degrees and the fan did not turn on.

At 95C both fans should be spinning at the low speed. Does the car have air conditioning? If you turn that on (set cabin temperature to lowest), then when you hear the click of the compressor clutch engaging, both radiator fans should start rotating at the slower speed.

It is likely that at least one fan has worn brushes, and is unable to run. Even if just one is affected, neither will run at low speed, but the good one will burst into life when the engine reaches the higher temperature threshold (100C I think).

[Gasa]

..not a single fan turns on when the air conditioner is turned on, the compressor turns on but the fan does not.
I read somewhere that the plug should be removed from the brown temperature sensor and that the fans should work then, nothing happens even when I do that.

[DownUnderXM]

Supplying 12v directly to the fan motors is the most reliable way of testing them - but of course that's easiest with them removed from the car. It's possible that you have a faulty relay (BTW - have you checked the fuses for the fans), but in Australia, with experience on Pug 605s as well as my Xm, plus various Xantiae and a Pug 406, it's always been worn brushes (and sometimes worn fan motor bearings) that have been the problem.

With the aircon compressor running, have you tried manually starting the fans? I had one in the 406 that would keep running once I got it spinning.

Actually I did recently have another cause for a fan not spinning. I bought a pair of new fans for the 406 from Spareto, but they were one of the cheaper brands. One of the fans was slightly out of round, meaning it rubbed on the shroud. The shroud plastic was softer, and a deposit of melted shroud built up on the outside of the fan. When the engine stopped and the fan stopped spinning, the hot plastic cooled and glued the fan to the shroud. Next time I used the car, only the other fan would spin - at high speed - so I knew something was wrong. The stuck fan of course caused the fuse to blow. I was able to sand away all the deposits and high points, so both fans now work perfectly, but the other downside of the cheaper fans is that there is a lot of noise and vibration at high speed. Fortunately we are going into winter, so it won't be a problem for a few months now.

[Dieselman]

I can't see an idling diesel getting hot enough to activate the fans, but to test they do work.

The fan control relays are mounted behind the headlamp and do suffer poor connections due to corrosion. Also, due to your car standing, one, or more relays could be stuck.

Use a high wattage test lamp (55w) at the relay connections to see whether there is power being supplied.

Check both the load power from the engine fusebox to the relays and also the Ign switched power via F9.
Both fans use a single Gnd point, m2, which I think is behind the left headlamp.
Pull out relay 813 and check there is power at Pin-3, if so, shunt Pin-3 to pin-5 at which point the fans should both turn at slow speed, due to being run in series.
Relay 815, Pin-5 would be a good place to check for Gnd as it is the connection for both the relay and the fans.

In slow mode, relay 813 supplies power to one fan, which then passes through relay 815 and powers the second fan. Due to currently being connected in series they have twice the resistance so run at slow speed.
For fast speed relay 813 supplies power to one fan, relay 815 switches, so now provides a Gnd link via Pin-5 and cuts the power supply to the second fan. Relay 814 switches on and provides power to the second fan.
The fans are now running in parallel, so run at full speed.

Relays are just switches controlled by electrical power. Being creative, you can bypass the relay and force the device to operate, but ensure you are connecting to the correct load terminals. Check and double check, then perform your tests. A pair of snipe nosed pliers makes a good test tool to temporarily connect the relay holder terminals for testing.

See Gabor's circuit diagrams for information.
download/file.php?id=9711

What tool did you use to fit the rear engine torque bushing?

[Gasa]

...I will see today to see what the problem is, 2 months ago it turned on the fans, and when the air conditioner was turned on, one fan worked, now when I turn on the air conditioner, only the compressor works, not the fan.
Thanks for the detailed answer.

[Gasa]

...I checked the relays, I tightened the contacts, only one was in worse condition, now they have good contacts.
When the engine is running, through the test lamp that is connected to -- and I touch this connector on the relay, one fan starts working, when the engine is turned off, the fan does not work.
The same connector on the relay, when the engine is off and the test lamp is on + the same fan works even if the ignition and engine are off.

..at this temperature not a single fan turns on.

ccvv.jpg

...on this contact the fan starts, only when it is bridged or on - when the engine is running, or on + when the engine is not running.

IMG_20230424_175341.jpg

..with the engine off,and on +

IMG_20230424_175327.jpg

[Dieselman]

You would probably learn more by pulling the relays out and performing tests to see which terminals have power and which have Gnd.

Theoretically that is relay 815, which is the inverter relay, but the wiring colours don't match any wiring diagram I can find. Are you sure you are on the correct relay?
It appears you are feeding power into a relay coil, but due to the relay still being installed can't tell whether theis is the +12v side, or the Gnd side. It seems odd for the relay to operate if you are connecting to the Gnd side, so it stands to reason this is the +12v side.
If that is the case, you are missing the +12v feed for the control side of the relays.
The +12v feed are a continuous one from the engine fusebox to relay 813 for the slow speed and an Ign fed one to relay 814 for the fast speed.

The pins for all these relay equate to:

Pin 1 = relay connection 85. Relay +12v
Pin 2 = relay connection 86. Gnd connection. This is shunted to Gnd by the coolant temp control board to switch the relay on.
Pin 3 = relay connection 30. Common load connection. Relay 813 and 814 should have this Batt feed at all times. Relay 815 will have this only when relay 813 is active and the fan motor has continuity.
Pin 4 = relay connection, 87a. Normally closed. Goes open when relay is activated.
Pin 5 = relay connection 87. Normally open, shunted closed when the relay is activated.

Relay guide
https://www.12voltplanet.co.uk/relay-guide.html


Please see link the pepon site which has original Citroen wiring diagrams for Series 2 cars.
You don't list your Rp number, but I checked all the single and twin fan setup diagrams.

http://pepon1.free.fr/CITROEN%20XM_fich ... shemas.htm