volt meter problem

[macspratt]

Hi guys, just noticed today after having my belts done last week thet the volt meter keeps dropping down to just over 12,will stay there for 10 secs or so or even 30secs then go bk up to norm.
Took the car bk to garage to get the alty belt checked,everything ok there ,no sliping,just seems strange problem came within a day of belts being done.
I repleced the battery only a few weeks bk,maybe i hadent noticed there was a fault coming.
does this soud like the alty is on its way out ,or would it just pack up altogether?.
The battery light isent coming on or anything.
will check pin conections tomorrow.

regards aidan...

[Muad_dib77]

Mine is always just over 12v... thought that was the norm... never had any problems..

[CJ]

Sounds to me like the diode pack (rectifier) in the alternator may need replacing in the near future. I had exactly the same problem about a year and a half ago, while it wasn't causing an issue as such, I had an auto electrician check it out for preventive maintanence purposes, diode pack was replaced and problem was solved. The battery light would come on very dimly for short intervals when driving, you could only just see it at night.

Mine is always just over 12v... thought that was the norm... never had any problem

The alternator generally charges @ 14V, when lights and a/c gare turned on you may see it dip slightly.

CJ

[Muad_dib77]

Oh... so I could be having a problem???

How much is one of those rectifiers? A Fortune?

My batterylight doesn't come on while the car is running - or atleast I haven't noticed it... Will be keeping an extra keen eye on it now though..

[CJ]

Oh... so I could be having a problem???

Don't worry about it unless the voltage reading fluctuates dramatically. I would expect a rectifier to cost about €150 or so.

CJ

[macspratt]

so when the voltage goes down to just above 12 or so ,thats the actual charge rate as opposed to 14 the norm?
does the alty need to come off to replece the diode pack,as it seem this can be troublesome to remove,does the drive shaft need to be split,or the mamifold come off to get it out?

edit http://www.autoshop101.com/trainmodules ... lt101.html

[Hercules Q. Einstein]

On my FTO when I turn on the indicators the voltmeter ticks between 14v and 12v (like a metronome).
Any ideas?

[kevinod]

On my FTO when I turn on the indicators the voltmeter ticks between 14v and 12v (like a metronome).
Any ideas?

I'd have to guess a bad earth somewhere, check your indicator wiring.

[Hercules Q. Einstein]

Cheers, yeah I thought it might be caused by the stereo not having a proper -D.C.

[CJ]

I'd have to guess a bad earth somewhere, check your indicator wiring.

I'd be inclined to agree, I have the same problem myself as it happens.

Older Jap cars are known to develop earthing problems, this can often be fixed by fitting a grounding kit. Basically, its a collection of wires that are straped on the negative terminal of the battery and then terminated at various points around the engine bay. Fitting such a kit is on my to-do list!



CJ

[Muad_dib77]

Am I right in thinking that I could do that with a negative battery terminal that supports multiple wires and some high-grade wire?

Have seen these kits sell for 25-45gbp on eBay - but I happen to have a bunch of stuff lying about the house that might serve well. (High gauge amp wireing and stuff)

[CJ]

Am I right in thinking that I could do that with a negative battery terminal that supports multiple wires and some high-grade wire?

In a word, yes. Most of the kits are made up from high gauge audio power cable - if you have some knocking about and you you have access to a crimps and eyelets, its a much cheaper route.

CJ