Coldest its been in years an my Heater Fan stops working!!

[Scottd]

Typical!! And scraping the ice from inside the windscreen every two minutes aint an ideal way to travel to work in the morning! And the only advice I've had so far is to stop breathing, so... I'm hoping for some slightly more constructive advice here

OK I did have the heater on full blast for the longest time ever, about two or three hours, while I was digging the car out on Monday. Probably not the best idea but I just forgot about it. It worked after that for a bit too however. It was only when I went out at lunch time it stopped working?

It doesn't work on any setting. A (very) little hot air still wafts up by itself thro the vents. The fuse is fine (god why can't it ever just be the fuse!).
Looking at the handbook there's a Relay thingy(?) for the heater fan next to the fuse box, I've no idea if it might be that or how to check if that's still ok?! Failing that, whats next to check? The heater fan itself? I've replaced the heater matrix before (oh boy was that fun ) and the fan is right next to it.
iirc I'm sure the fan is shockingly expensive!?

I'm guessing there must be some sort of other electric gismo in the pipeline there, to control the power of the fan depending on how you set it with the heater control?

Any ideas!?

cheers

scott



pre-digging out

[j2 lot]

My guess would be the resistor pack has gone ( common fault). Bad news is its not a quick fix and although the part itself is less than £100 the clam will probably need to come off to fit it so it ends up being costly.

EDIT
Just realised its an S1 so don't know if that is the same prognosis for fault (or fixing it) as the s2.

[Shug]

My first throught would be to replace the relay - cheap from a motor factor, just take it in. Otherwise, not that genned up on the fan on the S1, but I don't think the same resistor pack issues present as they do on the S2 - I believe that was an "upgrade"... Hopefully not a full fan replacement required - not a clam off job AFAIK, but as you'll have experienced with the matrix, a total c**t...

[Scottd]

Cheers for that guys.... so I thought, come saturday morning I'll go an get a new relay.... Friday night on the way home it suddenly starts working again!!! All settings, perfect. What the f@k!???

[robin]

To test a relay, first check your horn beeps. Then look in the user manual to see which relay the horn relay is. Then put your suspect relay in the horn position, beep the horn. It is beeps, the relay is good. If it doesn't beep, but starts to work again when you replace the relay with the original horn relay, then the relay is bust.

Your motor cowling may be cracked which might cause the fan to jam.

Or the intake might have been packed full of snow which then froze in the fan cowling.

Or, more likely, you have an intermittent electrical fault - dodgy connector, dodgy earth, etc.

I seem to remember that you can just about see the resistor pack + wiring from the drivers side of the services compartment - you might need to wiggle off that big alu air duct to gain better visibility.

Step 1, take a good photograph of the wiring as is - the resistor pack wiring is easy to put back together wrong.

Step 2, remove wires one at a time, with the fan turned onto full speed, and measure the voltage at the end of each wire to see if any change as you turn the fan on/off. Repeat with each fan speed setting. You should find three wires that turn on/off as you turn the fan speed up/down. If you do then the path from ignition->fan switch->resistor pack is OK. Next step would be to check out the earth side, but I'll need to look at the wiring diagram when the time comes to remember how that works.

Cheers,
Robin

[Scottd]

Cheers for that Robin, one extra piece of diagnosis is it is definitely temperature related.
When there's ice on the inside of the windscreen it doesn't work, like on Monday morning. But was fine again later. But I don't think it's a case of the fan being physically blocked with ice or anything. It either works 100% sounding perfect, or doesn't work at all.

I'm stumped!

scott

[robin]

Perhaps the temperature changes are just enough to wiggle something loose that should really be tighter - e.g. a dodgy connection somewhere?

Really you'll need to trace the voltage around the circuit to see where the break is and take it from there. Could be done with a wiring diagram and a multimeter and some patience.

Either that or turn on the fan, pop the bonnet and wiggle the fuse board, relay board, any loom connectors you can see as well as the motor connections and see whether it springs into life ...

Cheers,
Robin

[j2 lot]

It really does sound like the S2 resistor pack problem which starts with intermittent fails then returns to normal operating until eventually it dies, sometimes the process can take several weeks before it is completely gubbed.
But I add again that I don't know if the S1 has the same issues/parts as the S2.