Battery or Alternator trouble. Sound clip in post

[Maximusprime29]

Hi Guys, I own a 172 02 plate and have been having a few issues with it this weekend. I went to start it one evening, and it turned over very slowly, once, then nothing happened. I assumed the battery had gone and charged it. It started fine the next night so I took it for a long drive to give it some power. (No warning lights at all)

Once i got back i turned the ignition off turned off auto lights and tried to start it up again. the engine wouldn't turn. (STOP & Battery dash lights on, but thought this happens at ignition anyway?) I just got some very odd sounds from the ignition area, possibly closer to the engine bay. I'm guessing its the alternator thats gone, but i recorded the sound to see if any one could help identify whats going on.

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At first you hear the keys turn, at around 4 seconds theres a buzz as I'm trying to start. then an even deeper buzz/rattle. so i let the keys off and leave the ignition on and it goes back to the first buzz followed by some air-y clicking sounds Ive not head before, until finally the blowers come on at around 14 seconds. Obviously i stopped doing this straight away to avoid damaging something else.

If any one has any thoughts on what might be going on it would be good to hear.

Cheers

 

[MRBILLYUK]

I can't hear your recording.
When you turn the key to position 1 all the lights come on then go out after a couple of seconds. The only lights that should remain on are Battery, Stop and Handbrake. Then when you turn the ignition on to start the engine all the lights go off, handbrake obviously will remain on.
Does it sound anything like this ?
If so it's probably a loose earth like mine was or your battery is old and knackered.

 

[Maximusprime29]

I can't hear your recording.
When you turn the key to position 1 all the lights come on then go out after a couple of seconds. The only lights that should remain on are Battery, Stop and Handbrake. Then when you turn the ignition on to start the engine all the lights go off, handbrake obviously will remain on.
Does it sound anything like this ?
If so it's probably a loose earth like mine was or your battery is old and knackered.

Same situation with the dash lights. Yeah sounds very similar, I'm basically getting a combo of the two videos you posted. But that buzz sound when you turn the key for sure. Was the loose earth from the battery or from the engine?

 

[MRBILLYUK]

Same situation with the dash lights. Yeah sounds very similar, I'm basically getting a combo of the two videos you posted. But that buzz sound when you turn the key for sure. Was the loose earth from the battery or from the engine?

The buzzing sound is normal when you turn the key to position 1 . I think Its just the fuel pump priming.
Mine was the earth from the battery but I also bought a new earth strap for the gearbox to chassis. It was only about 8 quid from Eurocarparts. The original wasn't actually in that bad of condition so I just fitted the new one over the top of the old one lol. The holes were a tiny bit smaller for the bolts so I ran a drill through it to open it up.

It your battery is old and not holding a charge it's time for a new one.

 

[Maximusprime29]

The buzzing sound is normal when you turn the key to position 1 . I think Its just the fuel pump priming.
Mine was the earth from the battery but I also bought a new earth strap for the gearbox to chassis. It was only about 8 quid from Eurocarparts. The original wasn't actually in that bad of condition so I just fitted the new one over the top of the old one lol. The holes were a tiny bit smaller for the bolts so I ran a drill through it to open it up.

It your battery is old and not holding a charge it's time for a new one.

thanks for the help. I finally managed to get out to get a battery reading, it read 9.66 after i had the lights on for a couple of minutes to get rid of surface charge. but i couldn't start it to test the alternator, it's still making the same noises.

Is this likely the battery has gone or more likely an earth issue?

Cheers

 

[MRBILLYUK]

thanks for the help. I finally managed to get out to get a battery reading, it read 9.66 after i had the lights on for a couple of minutes to get rid of surface charge. but i couldn't start it to test the alternator, it's still making the same noises.

Is this likely the battery has gone or more likely an earth issue?

Cheers

The battery should be around 12.6v for a good battery. After leaving your lights on for a few minutes it'll probably drop ever so slightly.
9.66v is very very low. So it's either not charging or it's knackered.
With the engine running if the alternator is working the battery should be around 14.3v or above.
It could be a bad earth or the connector from the alternator causing this or like I said your battery could be old and knackered.

 

[joel93]

The alternator power cables are known for snapping (big red one bolted to the side of the alternator) and the alternators are notorious for giving up all together.

 

[Maximusprime29]

Did a thorough check with the multimeter - earths all fine, alternator was fine. Battery was slowly depleting after the engine was turned off, so replaced the battery and all seems good now.

Thanks for the advice!

 

[MRBILLYUK]

Did a thorough check with the multimeter - earths all fine, alternator was fine. Battery was slowly depleting after the engine was turned off, so replaced the battery and all seems good now.

Thanks for the advice!

Nice one. Glad you got it sorted.