VW Bora 1.9 TDi 130 bhp - Heater problem

[T3J]

Hi all

This week I noticed that my fan switch wasn't working on numbers 1, 2 and 3, but on 4 it was ok and producing heat etc..

1. The fuse is ok (25 amp)
2. Heat blower is fine (but I think over 11 years of use and current mileage at 206k it can do with a clean or replacement)
3. The resistor pack - not sure if this is the cause - as I have read this could be easily changed with a trip over to Maplins
4. Relay - but as everything is sort of working I'm going to rule this out

can someone else who has come across this problem let me know what was there fix


Cheers in advance

[Crasher]

Only working on 4 means the thermal fuse on the resistor pack has blown, I prefer to fit new Febi units rather than a new thermal fuse, I only do this on Corrado resistors which I can't get new. I sell them for £25 plus postage (genuine VW is £68.11) but at the moment there is no UK stock.

[rick vandal]

Does this strike you as archaic technology when pulse width modulation control is available?

[Crasher]

Possibly but it is and has been the industry standard for fixed step blower speed control since Noah was a boy and ultimately it comes down to costs and marketing. Climatronic gets a variable control system using a J126 Pulse Width Modulated blower speed control unit but the system costs at least three times what a ballast resistor costs and the Climatronic option needs to have a clear specification difference to justify its additional cost, creating part of the package difference between a 1J22?? Trendline and 1J23?? Highline or a Basis, Comfortline or Trendline with optional PR-9AK Climatronic instead of PR-9AB Manual controlled air conditioning. As with everything in life it all comes down to money.

[rick vandal]

Did somebody mention Maplin? If you go to CPC Farnell and search for product HK00955 you find a 3A PWM for under £10, or £58 less than the VW price. These crude ballast resistors speed controllers are why Vauxhall SUV's have been catching fire. I squared R losses without a sink. QED.

[Crasher]

Vauxhall have released a statement that in all cases they have investigated, Zafira B's which caught fire had been repaired with no genuine fan resistors, but it does not explain why some caught fire when new. I have to repair RHD Corrado 4 speed resistors at the moment as we can't get new, I buy the thermal fuses from RS Components.

[rick vandal]

Have you considered auto reset thermal switches? They are used in domestic boilers and heaters.

[Crasher]

Not something I had considered, you (in my position) tend to think about preserving the way things are, except for pistons and cranks, the further out they go the better... I think modern types term it "thinking outside the packet" or something like that, not a habit of one's....