Hi,
When my 2013 MX5 Venture battery has been disconnected for a long period of time the internal blower fan stops working. The first time it did this I took it to a garage who said they reset the ECU and that fixed it and the fan started working again.
The same thing has happened again so I plugged in my ODBII which doesn’t report any fault codes and when I tried clear faults, it doesn’t fix it.
Is there anything I can do myself to avoid taking it back to the garage ?
thanks
Mike
I don’t know how they “reset the ECU” but have you tried disconnecting the battery again, waiting for a minute or so then reconnecting it again?
What is the battery resting voltage before switching anything on?
Try charging the battery for a while (hour or two) before attempting to switch on the engine and accessories etc.
Here is some unsubstantiated speculation. I’m very happy to be shot down here, but I would not be surprised if Mazda are being clever and allowing maximum re-charge current into the battery to begin with, simply by shutting down non-critical thirsty electrical loads for the first run if resting voltage is low. You might find hrw, mirror heaters, seat heaters also don’t work to begin with.
Hi
the battery was disconnected for about 3 weeks that what causes the problem.
Then when I reconnect it the blower fan doesn’t work
I have tried charging the battery but the fan won’t run
When it happened the first time I went on a trip of about 150 miles and it didn’t start working then or on the journey back
The garage told me there were some error codes, probably caused by the battery being disconnected for so long. I think they said they reset the ECU, is there another any other sort of control system they could have reset ?
After reconnecting it and finding that the fan didn’t work, have you tried disconnecting it and reconnecting it again?
When you say that the blower fan doesn’t work, are the lights on the climate control panel working? The heated rear window and recirculation indicator lights. The climate control panel is the controlling module for the heater fan.
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I haven’t tried the second disconnection, I will give it a go
When it happened the first time I thought it would a be a fuse or something I never even considered that the ECU would control the fan but then they fixed it simply by resetting it.
I will reconnect the battery and test those indicator lights. Thanks for the help
I re-connected the battery and started it up and now it’s all working again 
Maybe it was the double disconnection and re-connection that did it !
PS I’ve noticed the screen blower is very powerful on the passenger side but much weaker on the driver side I guess it might be a bit blocked with leaves or something?
Is that easy to sort out ?
It’s biased towards the passenger side by design. Look down it through the windscreen and you’ll see that the vent outlet below the grille is off set slightly.
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