Interior fan driving me crazy

[Puggy2]

Hi all this is getting stupid. Have owned my 2.0 HDi for 3 years ever since I have had it the internal fan has had a mind of its own comes on when it feels like it sometimes works for a month sometimes a few minutes. Anyway my wife also has a 406 as well all working so I have swopped the fan control unit over and mine works her car so no problem there, a few months ago I joined the 2 wires from the ignition switch to see if it was the ignition switch. I then discovered by accident that the connector in passenger footwell with the red to green/yell & black to grey was causing the problem I could make the fan go off by wiggling the wires so I cut the connector out and crimped the 2 pairs of wires. This is when it starts getting crazy, now the blower runs at full speed even in aux position on ignition with no control from dashboard so I removed the joint at the ignition switch and the blower now does not work at all, is there something in that connector ? Sorry for the long post Iain.

[scotty73]

there's another one?

[puggy]

Mmmmmm seems so scotty

[Puggy2]

So no one knows then.

[FarmerPug]

The motor goes to a resistor, and then to the climate control. When you say fan control unit do you mean the resistor or climate control.

This is the resistor part:
http://www.ebay.co.uk/itm/NEW-HEATER-BL ... 4d099560e8

Its located in the footwell area to the right of the blower motor.

[Puggy2]

I mean the resistor which really is a bit more than a resistor, it is a transistorized speed controller.The bit that is getting me is just by making a permenant joint on the 2 cables has caused so much trouble.

[FarmerPug]

Any alterations to the electrical system on a pug can do this sort of thing, especially if its multiplexed is your car newer than 2001?

[Puggy2]

No 2000 pre comm2000 stalks etc

[FarmerPug]

When you crimped the wires is there any change the wrong wires got connected together? Or was it done just to bypass the faulty plug/connector.

[Puggy2]

Just to get rid of faulty plug, I am fully qualified mechanic/aircraft electrician

[Puggy2]

Just bringing this back as I still can't work this out.


Hi all this is getting stupid. Have owned my 2.0 HDi for 3 years ever since I have had it the internal fan has had a mind of its own comes on when it feels like it sometimes works for a month sometimes a few minutes. Anyway my wife also has a 406 as well all working so I have swopped the fan control unit over and mine works her car so no problem there, a few months ago I joined the 2 wires from the ignition switch to see if it was the ignition switch. I then discovered by accident that the connector in passenger footwell with the red to green/yell & black to grey was causing the problem I could make the fan go off by wiggling the wires so I cut the connector out and crimped the 2 pairs of wires. This is when it starts getting crazy, now the blower runs at full speed even in aux position on ignition with no control from dashboard so I removed the joint at the ignition switch and the blower now does not work at all, is there something in that connector ? Sorry for the long post Iain.

[jonsowman]

It might be the speed controller as previously mentioned, the fault just happened to occur at the same time.

The "blower running full speed" thing is almost always this control unit.

The transistor fails closed, but it's not a random failure. It will only occur when the controller is set to full speed - it then sticks there. So during your experimentation to see whether your fix worked, if you tested at full speed, that could have triggered the transistor failure in the unit.

Swap the control unit from your wife's car - it only takes 10 mins and it'll tell you whether that's the issue.