Electrical fault - battery not charging

[piefacemate]

Hi all,

Slightly challenging year for the Mazda with a new engine, oil feed failures etc. Seems things aren't over.

Recently I had a failed battery and alternator, or so it seemed. The battery wasn't registering a high enough voltage when running, which the AA diagnosed as a failed alternator. Both battery and alternator were replaced.

The car however still seems to be suffering from issues with the power. When I recently took it out for a drive and noticed that the stereo was fading as it seemed to be running off battery alone. Immediately took it home and now it won't start as there's insufficient power in the battery.

Does anyone have any clues as to what else might be at fault given the alternator and battery have both been recently replaced?

Cheers,

Chris

[Mr MXT]

I spent ages chasing a problem with the westfield after my alternator regulator failed and took the battery with it. I replaced both and it was still running like crap.

Turned out the new battery was actually duff, so could be worth testing that? Mine was showing correct voltage until you put any load across it and it would drop. It wouldn't start the car.

Other than that - dodgy earth?

[piefacemate]

Would the battery be earthed in the boot? It leaked water into the boot earlier in the year, I stripped all the carpet out and it's now dry but a fair bit of surface rust. Condensation gets it a bit too.

[MG CHRIS]

First thing to check is if the alternator belt is tight enough you should have about 10mm or less movement up and down, if it's not tight enough the belt can slip around the alternator pulley instead of turning it this happened to me. Mayby worth replacing the belt just done mine today on my mx5 and was about to snap.

If that is check the terminals are tight and not full of crap etc and also the earth cable is properly earthed.

[piefacemate]

Alternator belt is new so shouldn't be that. Checked it and it appeared to be turning fine, was recently tightened too cause it was squealing something awful.

Earth sounds like one to check. Would that be some if the wiring that runs from the battery and bolts into the floorpan of the boot?

Cheers so far guys.

[chasdad]

I recently bought one with a supposed faulty alternator . Fitted another one at sellers house drove it home and it wouldn't start next day.think it turns out that the terminals weren't tight enough on battery

[howlinmadmartin]

Had a similar problem on my mk1, turned out because my batterywasnt bolted in correctly there was a small amount of chatter and the pos cable had broken all but about 4 strands on the terminal! New battery clamp and re-connected terminal and was good as new!!

[howlinmadmartin]

Had a similar problem on my mk1, turned out because my batterywasnt bolted in correctly there was a small amount of chatter and the pos cable had broken all but about 4 strands on the terminal! New battery clamp and re-connected terminal and was good as new!!

[howlinmadmartin]

Had a similar problem on my mk1, turned out because my batterywasnt bolted in correctly there was a small amount of chatter and the pos cable had broken all but about 4 strands on the terminal! New battery clamp and re-connected terminal and was good as new!!

[piefacemate]

Turns out the alternator itself was faulty.

Apparently nationwide autocentre don't bother actually checking that the parts work after fitting...

At least it was all covered by the AA!