!!!Citroen Dodgey Blower Help!!!

[Lola adventurer]

Hi all,

I have a 2010 Citroën Relay with a heater blower which won't run.

So far I have done the following;

Tested the fan off a 12v external supply and it runs.

Changed the resistor pack

Changed the speed control relay.

Checked if the connector to the fan is getting 12v on all speed settings, it is.

Tried a different negative using another wire going to the stereos negative, still no joy.

Any ideas? I'm stumped!!!

Thanks

[boreas7]

Without knowing how you have carried out all your tests its difficult to understand exactly the cause of the problem.

However to be certain, if it is possible to do this, you need to check whether there is a 12v supply with the supply cable connected to the motor, ie mutlimeter on dc volts, positive to supply cable, return to a good earth. If ok turn off the 12v supply and put the multimeter onto continuity and check the earth lug on the motor has continuity to a good earth. If you can carry out these tests with the motor in postion and connected, it will tell you if you have a poor supply or weak earth.

If all these test prove ok you may have a motor with an intermittant open circuit, can you assist the motor to start? It it starts with assitance then it has an on and off open circiut.

All of this is in principle, I've no idea whether it is possible to perform these insitu tests in reality.

[boreas7]

Just a thought, based on what the wiring diag. shows for a mk1 C3, the return for the motor goes to earth via the a/c / heating control panel. You may have a poor joint or broken wire there, this would explain why your tests/changes of components have not cured the problem. The fault may well be on this control panel or where the resistor or relay fit into.
You will have to do a slow continuity check component housing to component housing.