Xantia Heater Blower Strangeness

samtronic · Unread post by **samtronic** » 25 May 2007, 22:50

Hi,

some time ago I began having problems with the heater blower in my Xantia (with Aircon, without climate control).
Sometimes the blower wouldn't start and I thought: The ignition switch problem.
Then I installed a relay, which probably was a good idea, but didn't fix the problem.
I discovered that I usually could get it going by hitting it and thought: Worn brushes.

Well, today I took the fan out and was a bit surprised by the connection to it: From a square 4 pin (2-by-2) plug on the loom was 4 wires with spade plugs connected to a 4 pin inline connector on the blower. I was a bit more surprised to see that there was no resistor pack, but a bit of electronics in the blower housing.
I didn't think that the transistorised blower was used with the normal 5 step fan speed switch.

I disassembled the blower and yes, the brushes were very worn, but after a bit of cleaning the blower worked again.

Though one thing strikes me as odd: Even on the lowest speed setting (off) the blower is running at a slow pace.

And finally a couple of questions:

Should the blower run even with the speed selector set to lowest (off)?

And where can I get a pair of brushes (8x9mm, 15-20mm long) at a reasonable price (Denmark preferred)?

Regards,
Søren A.M.

Unread post by **Peter.N.** » 26 May 2007, 08:59

For brushes, look on ebay, just type in 'carbon brushes' (or whatever that is in Danish) There is a chap advertising brushes for power tools, if you give him the dimensions of yours, he may be able to help.

If the motor has the usual two transistor system, the heater control is probably just being used to alter the bias on the transistors, which means it doesn't have to carry a lot of current and thus makes it more reliable. The usual cause of intermittent operation is faulty transistors.

tomthered · Unread post by **tomthered** » 26 May 2007, 09:26

I had a similar intermittent problem and a mechanic friend went straight to it. Try underneath the glovebox there is a wiring connection, push that in firmly. also check the wiring to the fan. Mine was bed connections.

Unread post by **Peter.N.** » 26 May 2007, 14:12

...or even bad connections...

Unread post by **lolingram** » 27 May 2007, 19:16

Bed connections are definitely to be preferred...

...or even bad connections...