Ventilation fan has stopped

[HPsauce]

Oh dear, it's packed up again today, just as the weather is getting cooler.
Bit weird though, I've had a flat battery and don't know the cause, so do wonder if there might be some "connection".

Found the flat battery by accident this afternoon, not having used the car for a few days, just went out to check fuel level and the displays were flickering. Wouldn't turn over but hadn't lost any codes or times so not totally dead.

A quick half hour on a charger and it started OK so went for a short drive to give it a boost and warm it up for later when I do need it. Realised the ventilation fan wasn't working.

I'll have the covers off tomorrow and investigate again. I want to have a good rummage around the scuttle anyway as the washers are a bit feeble.

[27litres]

They're isolated electrically (change over relay IIRC). A connection would be nice though, but the D2 solar cells are older tech and only produce about 9V at a decent enough amperage to run the fan.
The D4's use the newer blue cells and are used to charge the battery - that's a nice feature.

As for the battery, it could just be a once off (going flat), but keep an eye on it.

The onset of cold weather will normally finish off an older battery nearing the end of its life.

If it turns out to be a parasitic drain that can't be found through the usual diagnostic method, or the battery goes flat every few days regardless of use (as in driving it every day should keep the battery topped up, but doesn't seem to), look at the alternator.

[HPsauce]

The battery is very new (weeks!) but I've been messing around in the car a lot with doors open, not least replacing the NSR door window mech so probably drained it down a fair bit. Though I did go to ADI after that which is a long run. It will get a good long trickle charge now (24hrs?) and I'll monitor it for a while.

I'm fairly familiar with the wiring around the sunroof/fan and have actually installed an isolator switch to disable the solar-powered fan. The way that all works if there is a drain it's somewhere else. Just odd the two things together, though with only a few short runs in recent days that may just be my perception not reality!

[HPsauce]

Originally Posted by HPsauce

Oh dear, it's packed up again today, just as the weather is getting cooler.
Bit weird though, I've had a flat battery and don't know the cause, so do wonder if there might be some "connection".

Intriguing, the cloud is thinning and I can definitely hear the fan slowly ticking over under solar power.

All working normally now; air belting out with ignition on and reverts to slow turnover on solar.

I wonder if the low battery voltage had somehow messed up the changeover relay and it was stuck in "solar" mode yesterday.

[HPsauce]

As it's now "winter" I disabled the solar sunroof with the isolation switch after the previous post.
Been using the car a bit today, after sitting parked all weekend, and it's all fine again.

That 10p per litre off petrol at Tesco is handy - topped up with 60 litres of Momentum while out and about.

[Green Goblin]

Originally Posted by HPsauce

Intriguing, the cloud is thinning and I can definitely hear the fan slowly ticking over under solar power.

All working normally now; air belting out with ignition on and reverts to slow turnover on solar.

I wonder if the low battery voltage had somehow messed up the changeover relay and it was stuck in "solar" mode yesterday.

I’ve just bought a fan from a8parts. I went ahead and ordered the fan ‘blind’ as it was pretty obvious it was that. In the recent hot weather the fan was ticking quite loudly and got louder and louder - a sure sign of a worn down commutator.

It would suddenly start working when bumped over a pothole or some such but wouldn’t stay working for very long before getting stuck again. I too have the solar sunroof. I specifically asked for a fan from a non-solar sunroof car for obvious reasons.

Is yours ticking at all? (I only ask as you said ticking over - was that a metaphor lol? Or just spinning quietly?)

[HPsauce]

Originally Posted by Green Goblin

Is yours ticking at all? (I only ask as you said ticking over - was that a metaphor lol? Or just spinning quietly?)

It was indeed a metaphor but yes, sometimes, at lower light levels when barely moving you can hear a slight repetitive noise as if something is off-balance or there's some debris catching on the fan.
Given my other issues with seeds, debris, blocked scuttle drains, ill-fitting windscreen bottom trim etc. debris was my first suspect. Not least because fiddling with a wiring connector made a difference when it first happened.

But yes, if it does degenerate, replacing it is an obvious next step.
That said, it's not consistent and normally it's smooth and quiet, certainly when the ignition is on and it's getting full voltage.

Also the solar function is now disabled for the winter.
I think I documented that somewhere, but it's very easy to just tap into the return (earth) wire from the panel into the passenger footwell electrics panel.
I just looped that off to a convenient rocker switch, placed on the transmission tunnel side panel, and only visible/accessible with the glovebox open..

[HPsauce]

The mystery continues. Last night it stopped again, for a while.
Car was cold and a bit damp having been unused since before Xmas. I only did a handful of short journeys at night over the evening, 1 to 3 miles each.

On one of those it was definitely not working at the start but after a mile or so it came back into life. On others I wasn't sure as they were quite short and I was on busy roads so not thinking about it.

Then this morning, still very cold but parked in the sun, I needed to go to the car so just decided to press the Rest button as a test. Fan started normally and quietly.
So I turned the ignition on (without starting the engine) and it was running smoothly, all the way up to maximum when I adjusted the speed.

I still think it's some sort of poor contact in the external wiring, affected by cold and damp, as the motor seems to run fine when it does run. Or could it be something wrong in the "hedgehog"?

[moltuae]

How easy is it to get to the motor terminals? If they're relatively accessible I think I'd probably attach a couple of wires to those (and maybe an LED or voltmeter) to be able to quickly verify if there's power getting to the motor the next time the fault occurs.

[HPsauce]

Good thinking, I'll investigate that when the weather improves.