Xantia heater blower

splat · Post by **splat** » 23 Aug 2005, 18:44

Well, yet another intermittent problem. The blower has stopped working altogether most of the time. However, occasionally is works correctly - all speeds, including auto, seem to behave fine and continue to do so until I switch the engine off and back on again, after which it doesn't work at all.
When the fan isn't working I can be driving along and it'll suddenly come to life at a seemingly random speed. When this happens even selecting the off position on the control won't stop it!
I suspect the control unit, or more likely a bad earth in the control unit circuit. Naturally Haynes offers two wiring diagrams - pre '98 and post '98, neither of which seem to be applicable. The pre '98 circuit doesn't have a control unit (must be for a non-aircon car). The post '98 circuit does have a control unit - does anyone know whether the circuit on pre '98 cars with aircon is the same as post '98?
I notice that a whole lot of things are earthed to the body at the nearside wing close to the battery. I'm going to clean up all these connections in the hope of a general improvement (the car has lots of other intermittent electrical gremlins, luckily most of them only happen occasionally). Are there any other major earthing points I should be aware of?

mattpc · Post by **mattpc** » 23 Aug 2005, 18:59

On Xantias without AC waggleing the key while it is in the igintion will believe it or not coax the fan to burst into life when it's not working!!! Give it a go- it's worth a shot.

davek-uk · Post by **davek-uk** » 23 Aug 2005, 19:15

It also works on A/C models - if like mine the fan power is slowly scrapping the ignition switch![:(][:(!]
Some time back someone on this forum was distributing a copy of rewiring details to bypass the main power feed away from the ignition switch. Does anyone here have these details? And are they simple to follow?
As you can see from my comment above I have to do something soon!

Post by **Peter.N.** » 24 Aug 2005, 03:50

If its and 'auto temperature' type, its probably the transistors on the blower. You can replace them although an easier option would be to fit a second hand blower.

Post by **RichardW** » 24 Aug 2005, 13:31

Dave,
Here's a link to wiring diagram I did a while back (Excel):
http://www.geocities.com/tricky992002/fanmod.xls
I've not done this, so it may be rubbish, but should be right. You need to remove the steering column shrouds (wheel needs to come off for this) then find the plug (only brown with 2 wires going in/out) split it and wire in the relay. Unfortunately you're going to need to reconnect the air bag before powering up to test the system - the SRS system may go into a tailspin if you switch on without the bag connected (observe the Haynes precautions!). If you tackle it maybe you can take some photos and write some words, and we can put a tips and tricks post together.

davek-uk · Post by **davek-uk** » 25 Aug 2005, 14:55

Cheers Richard. I downloaded the file and I'm pleased to say the wiring was as I'd expected it to be. I'll have to see if I have a spare relay, otherwise one will be on my buy list for next month! I'll take some photos and try and find the easiest way to fit - and then I'll report back. It would seem that this mod is worth doing before any ignition switch problems become evident.

djc1960 · Post by **djc1960** » 25 Aug 2005, 15:26

Presumably that'll be why the ignition key feels hotter than I'd expect when the AC's been running. I just put it down to the fact that I only use the AC when it's hot and therefore everything, key included, is hotter....Duh

Jade Falcon · Post by **Jade Falcon** » 28 Aug 2005, 03:05

I've noticed the XM's system has the tendency to sometimes stop working seemingly at random, though touch wood it's been working well recently.

kafkaian · Post by **kafkaian** » 28 Aug 2005, 05:36

I put some images in a thread which can be found at the link below. The problem with my intermittency surrounded burned pcb contacts within the blower itself:
http://www.andyspares.com/discussionfor ... ter,blower

splat · Post by **splat** » 02 Sep 2005, 18:09

It turns out my fan problems were all being caused by worn out motor brushes. Fixed for £4.70.

stevenlizuk · Post by **stevenlizuk** » 02 Sep 2005, 18:59

I have had the same problem a few times, the switch keeps getting fried so lots of trips to the scrappy for a new switch.
Can you buy the switch brand new without the ignition barrel?
Stupid design!!