Aygo Mk1 Electrical Power Drain

[fossyant]

Strange one this. Our Aygo Blue 60 plate has just started going flat overnight. New Battery fitted and its done it again. I've now unplugged the fuse piggy back for the dash cam and unplugged the power socket phone charger. No lights left on.

Can only think a faulty piggy back power supply for the camera.

 

Anything else I should look out for before booking it in a garage. 

[fossyant]

It's actually drained again in the last two hours. Charged for an hour, then drove to shop, then back fine. Just checked now and there isn't enough for more than a chug.

[Devon Aygo]

have you checked the Alternator is actually providing a charge?

With the engine running at 2000rpm put a multimeter between + & - Battery terminals you should see a maximum of 10amps without electrical load & 30amps or more with high beam headlights on & heater blower at maximum setting & between 13.25 & 15.25 volts otherwise the alternator is faulty.

[fossyant]

Thats my next move, although no light on, but could well be the issue.

Will check later. Currently on charge. Fortunately my son is very handy with cars and his mate was a Toyota technician so they should have a look at weekend.   

Positive side is I found the air con leak whilst looking for issues, could see bubbling where the sensor is bolted to the high pressure pipe. Quick nip up with spanners sorted it.

[fossyant]

Not the alternator as with everything on, I'm getting 13.6v on the multimeter.  What I have found is that the voltage is dropping very slowy, but enough to see on the voltmeter, and after say 10 minutes it's lost 0.2 volts.  Poking about I can hear a quiet buzz coming from the engine bay to the left side - so something is live. Next to pull fuses one by one to see what's causing the buzz.

[fossyant]

More poking about and pulling fuses didn't stop the buzz. Lay on the floor and could still hear it lower down on drivers side. Hmm.

Explore un-plugging connections and the alternator pully, and the body of the alternator is rather warm. Touching the body you can feel the buzz.

I'm guessing this is a faulty alternator / bad diode.  I'll order a Denso unit from ECP - in stock and my son will fit later - bit awkward for me to reach !

[Hornet3D]

Depends on the timing and the buzz but not every buzz is indicative of a problem.

 

 

5 Things You Didn't Know About Your Modern Toyota and Lexus - YouTube

 

[fossyant]

It was buzzing hours after the car was used. Replacement going on this weekend.

[flash22]

1 hour ago, fossyant said:

It was buzzing hours after the car was used. Replacement going on this weekend.

Sounds like a duff regulator (4 diodes in a pack) and the Battery is back feeding the alternator effectively turning it in to a motor - the buzz is the rotor trying to turn it could possibly pull 5-40 amps

[Hornet3D]

6 hours ago, fossyant said:

It was buzzing hours after the car was used. Replacement going on this weekend.

The video states that the buzzing from the Evaporative Emissions Systems (EVAP) can be heard two to three hours after the car has been used. 

[fossyant]

Brief update, new alternator fitted, and no parasitic power drain. All OK again.

[Hornet3D]

1 hour ago, fossyant said:

Brief update, new alternator fitted, and no parasitic power drain. All OK again.

Glad you managed to get it sorted.

[fossyant]

We've only had it since November more as a stop gap for son (modded car that was broken) to get him to work, then for daughter to use if/when she starts to learn to drive. 

It's great for popping to the shops as neither my or MrsF's cars are great in city traffic with fuel (Nissans).

We've had a few issues with it, but we picked it up for a good price, so the extra costs are OK.  We were away this weekend, so asked my son to replace it. He did after fitting a lowering kit to a mates car !  Glad I've also found the aircon leak. Its been a very long time that I've not had A/C.   Essential on warmer days.