Volt meter fitted

[Hamish]

32 minutes ago, EliTR6 said:

A bit late to the party here but I also swapped my ammeter for a voltmeter by connecting the wires together behind the dash. 

With cold weather, lots of short trips and sometimes a few weeks between drives, I like that I can check battery condition just by looking at the gauge. 

Thanks Eli and the rest of the gang including those that PM’d info. 
 

gives me some options to think on. 
 

my biggest problem is I just don’t “get” electrickery so struggle to be “logical” I need step by literal step instructions. 
which is impossible as there are always individual peculiarities to our cars.
 

but I will get there.  

[tthomson]

On 1/25/2021 at 10:17 AM, Hamish said:

I’ll have to have another look and come back to you guys for advice on this one as I have a number of wires on the back of the ammeter.

so thank you. 
 

H

PS just for info my car was Tony Thompson’s so there will be very good and safe reasons for any deviation. 

For clarity,

I am Tony Thomson, not Tony Thompson - who is clearly a different person!

TT

[Hamish]

17 minutes ago, tthomson said:

For clarity,

I am Tony Thomson, not Tony Thompson - who is clearly a different person!

TT

Sorry. 

 

[tthomson]

Hi Hamish,

Nothing to apologise for. I didn't want anyone thinking I was someone I am not.

I assume the person you bought from was a Tony Thompson, otherwise I need to check in my garage! 

TT

[Hamish]

1 hour ago, tthomson said:

Hi Hamish,

Nothing to apologise for. I didn't want anyone thinking I was someone I am not.

I assume the person you bought from was a Tony Thompson, otherwise I need to check in my garage! 

TT

I’m very wary about bu@@ering up all the hard work and expertise the PO of my car did. He obviously did a great job and I’m bull in a China shop changing things - that’s old car ownership I suppose we are only custodians after all. A bit like old buildings tell a story through history by the changes and additions. 
 

sorry work distracted from replying to Pm.

[Bfg]

Voltmeter is useful to advise of both a static charged  and a charging state (in Volts), the digital one I use was a few quid from China, via ebay.  It plugs into the cigarette lighter. If it reads below 11.5 volts, with the ignition turned on, then I might have issues starting the vehicle ..presently in my old Diesel Chrysler.  As soon as the engine starts and the alternator is working then the digital voltmeter goes up to 14.2 volts.  With an old vehicle, it's reassuring to know at-a-glance that the charging system is working as it should.  An ammeter will likewise show this, and again it will indicate how much charge is being fed into the battery.  

An ammeter indicates the balance of current flow (Amps) ..both positive flow into the battery, and negative flow (discharge) from the battery.  So its advantage over the voltmeter is that can indicate the amount of discharge  at any moment in time.  And that can be quite useful, perhaps for example ; if you have under bonnet light, or one in the boot, that hasn't turned off.  The ammeter will tell you 'something' is drawing current from the battery and although it's not much, given time it will drain the car's battery.  Unfortunately, it doesn't tell you what has be left on, but at least you know to look for something.  In diagnosing a fault you can just pull a connection apart or take a bulb out ..if only to eliminate a suspect circuit from the search.  Marco's summation is very good in regard to the confusion this can and often will cause.  The ammeter's reading from an electric fan, for example, still running after the ignition is turned off, might at first sight cause you to panic.  But once the fan turns off ..then you have the quick-glance reassurance that nothing has accidentally been left on, including your side lights !   A volt-meter doesn't tell you that it just says you have 12volts left in the battery.

It may be noted that I said that the ammeter indicates the balance  of current flow..  + from the charging system, and - from everything that consumes electrical power = the ammeter reading.  And that again is very useful because, a vehicle with headlamps and heater ON  may draw more power from the battery than the dynamo or alternator is putting into it, especially when the engine is just ticking over. That discharge is fine as long as it's just a temporary situation, such as stopping at traffic lights or when you pull up to a garage.  But when the fan belt has snapped - then an ammeter is very much more informative than a warning light - because it can also help determine what power savings you need to make to get to your destination.  Almost certainly the fan heater and radio can be turned off,  possibly the windscreen wipers might be turned off when not really needed, and likewise turning the headlamps off ..to drive only on sidelights (where it's safe to do so).  I recall all this from my days with a MkII Spitfire when i was in my mid-twenties (..not recently then Pete !)  

As an aside, the ammeter on my motorcycle is situated in an electrical box under the saddle, which is conveniently near to the flywheel - so I use it to statically set the ignition timing ..as the ammeter's reading very clearly jumps as the points open.    

My boat has a dual digital-meter showing both volts and current, and it's switchable to various boat circuits ..such as house batteries or engine-starter battery. The ammeter is especially useful when you have things like house lights, navigation lights and other electronic consumables, but there's no charge going into the battery ..because your sailing.  Monitoring the rate of discharge can be essential to the vessel's safety. The ammeter is the best tool for that.  However the voltmeter is best when you come onto the boat or have been charging the batteries, because it indicates how much charge they presently have * in them.

* NB. the charging device or shore power / charger needs to be turned off for a moment to ascertain that, otherwise the meter will show a voltage from the charger, alternator or solar panel rather than from the battery.

In short, they are both useful instruments ..once you know what they are telling you.

Pete

p.s. a voltmeter can also be useful for those who have electronic ignition, because these require a certain minimal voltage to work. Much below that figure the vehicle just wont start.  

Edited January 28, 2021 by Bfg

[Nigel C]

I've got all the parts to do a swap from Amps to volts but I was going to re-manufacture the face of the volt meter to "look more in keeping" with the dash/period style. Just a bit of artwork and then get it printed by one of my suppliers...... of course that was a Sunday morning pillow idea about 20 years ago and still on my list 

 

Has anyone experienced an Alternator's regulator packing up and send s**t loads of amps down the loom?

 

[North London Mike]

LNK also has a custom Voltmeter, better and safer than an Ammeter (IMHO). I have learnt to read it over time. Cold start, headlamps on and it will read 12v quickly coming back to 13/14v which is where it tends to sit, very happy and as Rob says, you pay your money and make your choice !

 

[Z320]

Hi,

until now nobody was able to convince me from the benefit of a voltage gauge.

It is the same way dangerous as a ampere gauge, the same way as every cable with 12 V on it.

And even more when you connect it without a fuse (I'm shure all of you did it that way)!

Why should I fit one? It is obvious what it always will show me.

Ciao, Marco

Edited January 29, 2021 by Z320

[Ian Vincent]

It's a fair point that the cable to an ammeter is a chunky piece of wire running behind the dash (well mine is anyway) so it probably is a good idea to put a fuse in it, but otherwise I like the information that the ammeter provides, and it's how the car was supplied.

Rgds Ian

[Z320]

I did not recommend to put  a fuse in the cable to the ampere gauge - but you can do.

[Hamish]

Well this weekend I bit the bullet and decided to join the wires behind the dash ( makes it easily reversible modification. Rather than joining in engine bay and deleting cables) i found these or similar which made it simple and safe. With added insulation tape.

CLASSIC CAR SPADE TERMINAL / LINE SPLICE connector 4 way insulated BRASS x 2

https://www.ebay.co.uk/itm/301548678074
 

the tape I apply sticky side to sticky side so it seals really well and tight around the wires. And doesn’t unpeel like it can if you do the overlap wrap. Don’t have any amalgamation tape !
 

the oil gauge is also fitted to the dash (in ammeter hole) and the sender and wire/capillary are ready under the bonnet for when I fit the sump.

it started well and no Lucas or Hamish electrical smoke !!

sadly first time started since mot in NOVEMBER !!!!!

ran it up to temp rad fan etc still works. 
 

another little lock down job done in a warmer garage. 

[Nigel C]

well done and those spade terminals look a good idea. I used some of these on a job the other day and was very impressed.

https://uk.rs-online.com/web/p/splice-connectors/2393988/?cm_mmc=UK-PLA-DS3A-_-google-_-CSS_UK_EN_Connectors_Whoop-_-Splice+Connectors_Whoop+(2)-_-2393988&matchtype=&aud-827186183686:pla-353174063490&gclid=Cj0KCQiA4feBBhC9ARIsABp_nbUQUw__mwFZTfyJK-8bPFloVaV_Iozq7C09mo43lTtEetVa3gBYzrMaAoJuEALw_wcB&gclsrc=aw.ds 

Did you fit a volt meter, cant remember?

[Hamish]

1 hour ago, Nigel C said:

well done and those spade terminals look a good idea. 

Did you fit a volt meter, cant remember?

Thanks Nigel

yes fitted volt meter. See the start of the thread. 
both volt meter and oil temp gauge are after market look a like. But they seem to work and are in character with the rest of the dash. 
I’m keeping all the originals. Just in case. 

[RobH]

1 hour ago, Nigel C said:

I used some of these on a job the other day and was very impressed.

 

Just a word of caution Nigel in case others try them, those RS gel-filled insulation displacement connectors are intended for signal cables like telephone wires etc. -  not for applications where significant current is flowing - and are really not suitable for use anywhere on a TR except perhaps radio speaker wires.  

They only work properly with solid-core conductors of the right diameter and are akin to those rather iffy Scotchlok things beloved by bodgers.  

[Nigel C]

Hi RobH, fair point and I thought of the application I used them on (automated wind turbine models) and started to wonder....so I went out into the workshop (see the thing I endure for others!) to check exactly what I do have in stock. Turns out I have these which are more than man enough to cope

https://www.medlocks.co.uk/swa-uy2c-gel-filled-connector-2-way-yellow-bt-jelly-crimp-each 

 

[RobH]

Sorry Nigel - those are not designed for use with stranded cables - the BT bit in the name is the giveaway. 

These were designed for British Telecoms use as they can give a good enough signal connection without the use of a soldering iron when up a telegraph pole.  Personally I wouldn't use them for anything serious but that is just me.... 

Edited March 2, 2021 by RobH

[Nigel C]

oh, ok, it says up to 8 amps?

[stuart]

13 hours ago, Nigel C said:

oh, ok, it says up to 8 amps?

Definitely wouldnt use them on anything direct feed like the Ammeter or horns 8Amps isnt much.

Stuart.

[RobH]

It isn't so much the current rating - it's how the connection is made.  Basically it is a bit of metal with a vee-shaped slot in it, which its pushed onto the cable, cuts through the plastic insulation and bites into the cable core. It can only do that properly if the wire is a single solid core of the right size; multi-strand wires tend to push out of the way. 

The point where the core is bitten into is then a weak spot so can fail under stress. That isn't a problem with phone wires as there is no vibration and should be no tension but it might not be true for other uses. 

[ianc]

Rob is correct - the description states that these are designed for "solid copper conductor cable", and that is NOT what one finds in TRs (or any other cars of the era).

Ian Cornish

[Lebro]

I have always hated that type of connection, including "scotch blocks", & never use them.

Bob.

Edited March 3, 2021 by Lebro

[Nigel C]

I'll get me coat........

[John Reilly]

Is it possible to get a Jaeger voltmeter similar to the ammeter it might replace in the instrument panel?

John

[Ralph Whitaker]

On 1/29/2021 at 12:18 AM, North London Mike said:

9 hours ago, John Reilly said:

Is it possible to get a Jaeger voltmeter similar to the ammeter it might replace in the instrument panel?

John

LNK also has a custom Voltmeter, better and safer than an Ammeter (IMHO). I have learnt to read it over time. Cold start, headlamps on and it will read 12v quickly coming back to 13/14v which is where it tends to sit, very happy and as Rob says, you pay your money and make your choice !

 

See above,

Ralph