I’m looking for technical help or recommendations on: Parasitic drain
The car has a drain of approx. 340ma I have removed the power lead to/from the alternator just in-case it was a diode issue. Didn’t remove the other connection though. But still there seems to be a 400ma drain, which does drop down to about 340ma over time.
I then went back to re checking all the fuses, when removing the 15amp room fuse from the fuse board under bonnet the display on the multi meter drops to zero. With the 15amp room fuse re fitted all the fuse in the car footwell were removed, but the drain was still apparent.
Looking at the forum people mention the stereo, as It seems quite an issue to get to the back of the stereo, to see if there is an issue there. I.e. removing all of the central console, etc. Are there any other areas to look first? I have also changed the alarm siren as that was initially indicated as a possible cause.
I assume you have no aftermarket stuff like a satnav, dashcam, alarm, phone power adaptor etc. wired or plugged in?
But that you have removed all the footwell fuses and it made no difference, you can list at all the equipment the footwell fuses supply and assume they are not at fault.
Are there relays (in one of the fuse boxes or elsewhere)? Try removing them one at a time and see if there’s any difference. One may have got stuck closed.
Is there a Bluetooth OBD2 adaptor plugged into the diagnostic socket? (Under the dash, far right. ) I think that’s a permanent 12V and would cause a drain, although 4 days, probably not that.
(A reason for one to be there is if a previous owner used something like the torque app for engine monitoring. I unplug mine if I’m leaving the car for more than a few days.)
340Ma is excessive for these vehicles, spec suggests less than 100Ma to be normal.
The only way to trace this issue is to disconnect individual items that are associated with the relative fuse that reduces the drain when pulled from the fuse box.
If it’s the ‘room’ AKA ‘interior or cabin’ fuse then there are a number of components on that circuit that could be at fault..
Sometimes wiring diagrams can be your best friend but can also hinder, I would pull the fuse that drops the current , then see which components fail to function as before when the fuse was installed. You may be able to narrow down the list, but individual isolation is probably going to be the only way.
Radio, door locks, interior lights, boot light, ECU etc.
(A list taken from Google) =
ECU, transmission, audio system, power antenna, interior lights, instrument cluster, data lines, anti-theft and door locks.
PS, one last thing. Did the issue occur before the new battery was fitted ? I would also never discount a new battery not being faulty, as many new batteries have caused drain issues rather than fixing them.
These problems can be difficult to solve. With our Mini, I got a mobile autoelectrician to diagnose the problem, £100. As an intermediate solution, you can disconnect the negative battery terminal. An old thread here, which turned out to be the instrument cluster. Parasitic draw on battery - #10 by Timmahh
Thanks for everyone’s input. It was the Stereo. Have removed it from the car and the drain drops to under 30ma.
I have ordered a used one from a breakers yard, but it is the 6 disc one (NH58 66 9 RXA/NH58 66 ARX) and not the single (NH52 66 9ROA/NH52 66 ARO). Does anyone know if this will work?
Apparently the local Mazda garage say they are not coded??
I want to try and keep the car as original as i can, hence fitting another stereo, albeit 6 discs rather than 1.