Allegro Club International

J Dawson · Posted: Thu Oct 04, 2012 1:26 pm Post subject: Ammeter

I would like to fit an ammeter to my car. Can anybody tell me the way to do it with an alternator please?

Or would a voltmeter be more useful given the charging power of alternators?
_________________
Austin - you can DEPEND on it!

1976 Allegro 1100 4-dr saloon

Squeak, rattle & roll

giz · Posted: Thu Oct 04, 2012 2:34 pm Post subject:

go for a voltmeter, they are much safer and easier to use.
you just take one 1 wire to the +v of the battery and 1 to the -v side.

with an ammeter you have to slice through a cable so that the current flows through the meter, too much current = fire, poor connection = electrical gremlins.

plus voltage is easier to understand, 14.4v = good <12v = bad.

J Dawson · Posted: Thu Oct 04, 2012 5:12 pm Post subject:

Yes I am concerned about the fire risks, but wouldn't the voltmeter in that case be more dangerous by running wires directly from the battery? Battery cables are very hefty after all.
_________________
Austin - you can DEPEND on it!

1976 Allegro 1100 4-dr saloon

Squeak, rattle & roll

Richard Howe · Posted: Thu Oct 04, 2012 5:59 pm Post subject:

You have it backwards; the ammeter has to be run direct from the battery - in fact, it has to be between the battery & everything else on the car, so is normally fitted into the live feed. This means a couple of hefty pieces of cable carrying the entire current load into the dash & back out. Voltmeters on the other hand can go anywhere & run off anything - I saw one on FleaBay this week that simply plugs in as a cigar lighter accessory!
_________________
...that's why Allegro will look as good 5 years from now as it does today.

giz · Posted: Fri Oct 05, 2012 6:47 am Post subject:

volt meters are wired parallel to a circuit - no load, no fire, no problems.
amp meters are wired in series with a circuit - load etc etc

Richard Howe · Posted: Sun Oct 07, 2012 3:43 pm Post subject:

http://www.ebay.co.uk/itm/261056357412
_________________
...that's why Allegro will look as good 5 years from now as it does today.

J Dawson · Posted: Sun Oct 07, 2012 4:06 pm Post subject:

Thanks Richard but must be the period Smiths' gauge to fit in with the car.

I have my eye on one...
_________________
Austin - you can DEPEND on it!

1976 Allegro 1100 4-dr saloon

Squeak, rattle & roll

Laurence · Joined: 17 Jul 2007 Posts: 1408 Location: Plymouth

You don't need all that current to pass through an ammeter if you use an inductive ammeter, you just need an inductive loop which passes across the rear of the clamp-on type ammeter.

Google inductive ammeter, have a look on ebay. There are two types of ammeter, the inductive (proximity) ammeter may come with installation instructions, if not, let me know & I'll tell you how Smile

Paul-V · Posted: Mon Oct 08, 2012 8:35 pm Post subject:

I must admit that as a schoolboy I used to be fascinated by the ammeter in my Grandad's Vanden Plas Princess 1300 and the way the needle constantly fluctuated as electrical equipment was switched on and off (especially the indicators)

It was probably one of the last BL cars so equipped, as all Rovers and Triumphs from the 70s onwards tended to be equipped with voltmeters instead (much less entertainment value)

Graham · Joined: 15 Oct 2007 Posts: 625 Location: Hereford

The ammeter I fitted to my first Allegro was quite entertaining as well. You should have seen the faces on the passengers when smoke started appearing out of the dash and how quickly they all got out and scarpered!!!
I did have a moment of panic but the short circuit was, fortunately, short lived and no real harm was done. Shocked

ruSSell · Joined: 18 Jul 2008 Posts: 883

ruSSell · Joined: 18 Jul 2008 Posts: 883

J Dawson · Posted: Thu Dec 27, 2012 6:32 pm Post subject:

Fitted a Voltmeter in the end and a proper temp. gauge as my Christmas presents.

I will ask Giz to upload some photos in the 'General' section over the next few days.

The Voltmeter was indeed the right choice as an alternator is always going to whack out plenty of amps over a dynamo.

Thanks chaps for the advice. Smile

_________________
Austin - you can DEPEND on it!

1976 Allegro 1100 4-dr saloon

Squeak, rattle & roll

Colin T · Joined: 13 May 2007 Posts: 1282 Location: N.E. Hampshire

'Proper temp gauge'? Any more info on this?

As far as I know the original temp gauge on all models works lineally, with 'normal' in the middle.

Not like some cars which have electronic 'rigged' gauges, which can be totally useless in some circumstances - e.g. Rover 75, where the needle will be exactly in the middle position from anywhere between 75 and 115 degrees centigrade! No warning of dangerously high temperatures which can cause damage!
_________________
Hell has frozen over...... the car formally known as 'Heap' is back on the road!

J Dawson · Posted: Wed Jan 30, 2013 3:34 pm Post subject:

I had the photos ready and then the website went down... this reminds me.

The gauge replaces the useless original as it reads from 40 deg. C to 120 deg. C.

The car sits at just over 70 deg. C and the cooling fan kicks in at around 80.
_________________
Austin - you can DEPEND on it!

1976 Allegro 1100 4-dr saloon

Squeak, rattle & roll