Brand new battery showing 12.38 at terminals and car trouble

[markander46]

Hi Folks,

I'd been having what I presume to be battery trouble with my trusty old yaris. I went to drive it one day last week and the car wouldn't start. All the lights, radio, fan blower etc. worked, but the car wouldn't turn over. There was no clicking noises or even any lazy attempt by the car to turn over.

I imagined it might be the battery as I'd flattened it the week before by leaving an interior light on overnight, and maybe since that occured I hadn't done enough miles to recharge it properly.

A friend was good enough to come down and give me a jump again after I'd previously flattened it, and so this time I gave it a good run for an hour to recharge the battery. The next day the car started no problem. I had a journey of about twenty minutes to do, so off I went, upon returning to the car ten minutes later the car wouldn't start again, silence upon turning the key. I was on a hill, so managed to bump it. As you can imagine by now I'm starting to think the battery is goosed.

I was fortunate enough to get a jump again, but this time the friend brought a voltmeter. Before jumping it he tested the battery at the terminals. It was showing 12.4. After he jumped the car he tested the alternator with the voltmeter as he said maybe the alternator was no longer working. The alternator test showed 14.24 under no load, and about 13.78 if i remember correctly under load. He thought the the battery may have a dead cell so suggested a new battery. One thing that perplexed him, was that after he jumped my battery he restarted my car under it's own power while connectiing the voltmeter and the battery only dropped to about 11.40 or near as.

I took my friends advice and ordered a new battery and my own voltmeter. The battery has turned up along with the voltmeter. I tested it myself at the terminals using the voltmeter and it's was showing 12.38. I thought it should show 12.6 or higher? (it's the correct battery for my car) Anyway i fitted it to the car in hope, but yet again, silence upon turning the key. Lights, radio and blower are all working as normal. So have I ordered a duff battery? or is it maybe an electical problem? Should i also jump this new battery? I know of course you can't diagnose my car at your home, but any help on tests i can do would be welcome.

If you're wondering why I haven't took it to a garage, a recent illness has had me give up my job, and the funds just aren't available like they were previously. So I'll need to start learning myself if I'm to fix this.

[markander46]

Hi all,

Thanks for the replies!

Jet_Noise: thanks for that piece of info, i'll go try that now. I'll not be able to see my front headlights, but I assume by putting the interior lights on, they would dim too upon trying to start as well.

Krikkit: I'm trying to do a bit of reading about this, and I keep seeing starting motor come up too. (that and fuses) I'll go see where to locate the starter motor now as well.

Banjowilly: Loose engine earth strap. as you can probably tell by my intial post i'm a total novice at this, but i'll see if i can go and locate this earth strap too.

Thanks again all for the replies. You can all probably tell by now that engine mechanics and electrics are new to me, but we all gotta learn sometime right

Thanks to to whoever moved this to the correct part of the forum.

[markander46]

Hi all,

Thanks very much for the replies, and sorry for my late reply.

I'll try to answer questions asked and what I've managed to check.

So upon turning the key the lights don't dim, so one of the replies mentioned the starter may not being asked to turn. I found the starter motor at the back of the engine, unfortunately it is a complete nightmare to get to. I can barely see it, but managed to get a small look at it by using my phones light and recording, it doesn't look to be in great shape, in fact there appears to be a lot of rust about.

I did mange to do a ground test someone showed on youtube by connectiong the black probe of my multilmeter to the megative battery terminal, and the red probe to the starter motor body. I got the continuity beeping noise from the multimeter, but not at all points I put it on, but there was loads of heavy dust on the starter. I can't actually see the power feed to the starter as it's obscured.

Ive also tested all the fuses in the box in the bonnet, three that I read are responsible for starting, I visually inspected. The rest I used the continuity function on the multimeter and they all appear to be fine.

I got a shot of a battery charger from a friend and the orignal battery charged up no problem and appears to be good. That and having a new battery that's better than my old one, I think I ca rule out a battery problem now.

My friend also tried to jump my car with his jeep, but it wouldn't jump. I also noticed after my friend left and it was a bit quieter that I think my fuel pump is primimg..There's a noise coming from the back seats. I also noticed a noise under the bonnet, like whirring noise coming from either the back of where my ignition key goes or maybe a bit to the rright of it.

What I'll try now:

I'll try the jump lead from the negative to an area on the engine.

I've found another batch of fuses under the glove compartment, i'll test them for continuity.

I'll try get better access to the starter and find out how I can do more tests on that. Thanks for the saftey tips by the way

I'll try find out what this whirring noise is responsible for, or what it should be doing.

And, can someone please tell me how to test the grounds around the engine using a multimeter Should I be on ohms or volts? black probe to ground point and red probe on battery terminal or other way around?

Thanks again for the replies, it's appreciated

Edited to say I'll make sure the connectors are spotless too.

[markander46]

Thanks for the advice on the jumplead to a clean position on the battery.

This didn't make a difference when trying to crank. I found a clean spot on the engine, and also a bracket on the alternator to try from, but alas. However, as mentioned by penelope my jump leads might be a bit on the poor side.

Screenshot_2019-08-20-01-31-04-538_com.miui.gallery by Mark Anders, on Flickr

I also had a pal coming to help whilst I tested the battery and possibly the starter (though it's a nightmare to get to, can't even see it properly) but he has phoned to say he can't make it now, and he says "it's raining" So that'll need to be tomorrow now.

Access to starter, the video below doesn't show the difficulty getting to it, that was me with arm in back of engine. I may have to get it on stands from underneath.

access to starter by Mark Anders, on Flickr

Also I mentioned the whirring noise after trying to crank,maybe from ignition? That's where it sounds like it's coming from when you're near it. Hopefully someone may recognize this noise.


whirring noise from ignition sytem by Mark Anders, on Flickr

I was also surprised to see the new battery down at 12.19 volts as I was about to lock the car, maybe from me trying to crank and capture that noise? The car hasn't started the car, so the battery has done pretty much nothing, it was only fitted a few days ago.

IMG_20190820_170903[1] by Mark Anders, on Flickr

Thanks for all the replies again! I thought I'd try add a few pictures and videos rather than descriptions this time, so hopefully these embeds work

Edited by markander46 on Tuesday 20th August 19:38

[markander46]

Hi,

GTVOX, yes I'll try get the starter off today. I have a halfords ratchet set with extensions, so that should give me more reach, thanks.

E-bmw, Sorry I probably didn't word my reply right in the previous post. I actually did connect one end of the jump lead to the negative battery terminal, and the other end to a clean bit of metal on the engine as helpfully suggested by you in a previous post, thanks.

Yeah, the bit about the battery voltage was just an observation by me. It's a new battery (exide 50 amp, 450cc, stronger than my old battery) only three days fitted and already it's flat. I couldn't see how it was flat. as it's literally done nothing, but then again I don't know a lot about batteries.

I put back in my orginal battery to do tests to after I trickle charged it, as i now know there was nothing wrong with my orignal battery (Bosch silver) my problem lies elsewhere. Thanks again.