Radiator Fan NOT Working Xsara Picasso 1.8sx 2003

[admiral51]

The following is borrowed from Cloggz so thanks to him

You can see with the fan removed from the housing the plug /socket which is the one i was trying to refer to earlier as the motor plugs into this

Colin

[Fartblast]

The center screw was left-handed so no problem removing, thanks. I removed the fan motor from the mount and looked at the condition of the spade connectors on the plug and the socket. The socket looked OK but the plug connectors were a bit corroded on the ends so I used wet & dry paper to remove it. Rather than attempt to break open the metal fan housing, which is very well secured, I decided to see if cleaning the connectors had solved the problem so put it back together and fitted to the car. Unfortunately if anything it seemed slightly worse so no joy there. I then took another look at opening up the motor body which is very solid and crimped in five places on each end. It didn't take me long to conclude it was not worth the effort so I have decided to buy a second-hand fan off eBay, it should arrive tomorrow and I will let you know if it solves the problem.

Picasso-Fan-Plug

Picasso-Fan-Socket

Picasso-Fan-Motor

[white exec]

Progress!
Those metal tabs in your last photo will just bend away, and should allow access to the motor parts.
When you get your 'new' motor, check that its of the same type as the old one (casing numbers etc), and do test it before the final fit.

Worth opening up the old motor anyway, to inspect the brushes. If they do turn out to be worn, you could simply fit new ones (I can suggest some web sites that specialise), test the motor, and keep it as a good spare, just in case... I have done that with a cabin blower motor.

[Fartblast]

UPDATE:
Fitted the new (breakers yard) fan off a 2003 Picasso and although the housing was dirty and had obviously covered allot more miles than my car, the fan motor seems to be working fine, at least in A/C mode as I've not had a chance to get really hot yet. I did a resistance test on it and got reading 1.2 Ohms compared to my original motor which was 2.5 Ohms so I guess that was the problem. I just hope it gets me though the MOT booked for Friday. I would like to thank all who replied and especially 'white exec' who I know was trying his very best to help. This is a truly great forum and long my it reign.

[white exec]

Thanks for that - we do our best. Well done in getting things running again.
Measuring resistance across a brushed motor is a pretty haphazard business (it can vary as the armature is rotated), so don't worry too much about those readings.

[admiral51]

Congratulations a cracking result

The fan comes on at slow speed when A/C is switched on, so my guess is there is a HP/LP switch on the air dryer/receiver. Is there a way to to do the bridge trick like on the Xantia switch to trigger the fan into full speed with the engine running?

Until the engine gets upto temp to trigger full speed the fan will be running at slow if A/C is on.
We now know the replacement fan works as intended with A/C on just thinking ahead as whilst the OP is in a fault finding mindset ..........

[Fartblast]

UPDATE:
Picasso passed the MOT this morning and the engine didn't overheat. The reason why is due to the MOT tester turning up cabin fan and heater to help cool the engine which kept the temperature at three bars in stead of the normal two. So while the replaced fan appears stronger and the speed is better than before it looks like it still only works for A/C. That means I just wasted a lot of time and £43 on parts. At least I can still use the car as it does not overheat under normal driving conditions.

[admiral51]

Congrats on getting a pass

If the fan works as intended on the A/C side of things then the A/C ECU is happy that everything is fine.
This is one for those that can read/understand wiring diagrams but surely the power for the fan is one wire the rest is just triggering the relays to do set things?
However with relays removed by powering up one of the pins should set the fan going pin 3 from memory.
If the temp sender gauge has a different sender sensor for the Ignition/ECU then if that unit is showing a low temperature it will never send power to the relays to start the fans
?

Colin

[white exec]

Refer to my post here:
viewtopic.php?p=639551#p639551 and the circuit diagram.

OK, the AC is successfully switching on the fan, so that's good news, and means that Relay #1514 is doing its stuff, as are the dropper resistances (or at least one of them is!).

Now, to test Slow speed:
Connect line 1550 on the ECU to Gnd. This should bring on Slow speed.

To test for High speed:
Connect line 1540 on the ECU to Gnd. This should trigger High speed.

If these don't work you have either
- a relay problem
- or an ECU problem (far less likely).

Also, try unplugging the temp sensor (#1220).
This should bring on the fan, probably at High speed.
It is designed this way, to provide engine cooling even if the temp sensor fails.

All the tests above will require IGN on, and possibly engine running.
Your fan was obviously defective, so the money to replace it was not wasted!

[admiral51]

When i removed the plug on my thermostat housing on the Xantia it did not effect the dash temp gauge,i think the OP needs to find the right plug to unplug if that makes sense

[Fartblast]

This is the only temp sensor I can see. Do you know the location of the other one.

Picasso-Thermostat

[white exec]

That 2-wire green connector should be the Fan control temp sensor (#1220).
Try disconnecting that, with the IGN on (and maybe engine running).

I don't have the wiring diagram for your car, to find the details/colour of another temp sensor (for the gauge), if there is one.

The numbers of separate temp sensors were gradually reduced over the years. Originally three (gauge, injection ECU, water temp control), later two, and now (maybe) just one. Circuit diagrams would confirm.

Try pulling that green one, and see what happens - to either gauge, or fans, or . . . will engine run?

[wheeler]

When i removed the plug on my thermostat housing on the Xantia it did not effect the dash temp gauge,i think the OP needs to find the right plug to unplug if that makes sense

That's because the Xantia wasn't multiplexed & could have up to 3 coolant temp sensors for different functions. One of the reasons for multiplexing is to reduce the amount of unnecessary sensors & wiring. Whats the point in having 3 sensors that all read the exact same thing when one sensor could just share the information with other systems?
Its most likely the Picasso only has the one coolant temp sensor that will do the dash gauge, the engine management fueling & the cooling fans, If you unplug it with the engine running it should put the cooling fan on full speed, put an engine temperature warning on the dash & will probably log a fault code in the ECU too so remember to clear the faults afterwards. I also wouldn't recommend doing it with the engine totally cold as it can also make the engine run very rich which can flood the engine.

[Fartblast]

Pulled if off and all that happend was the dash guage went to max, which is what happend with old original fan. Then after about 12 seconds the fan went into warp drive! Looks like it needs a new temp sensor.

[Fartblast]

Going to order a new temp sensor. I think there were multiple faults with the fan, both resistors, the fan motor and temp sensor. Hopefully replacing it will solve the long standing engine cooling problems.