Wiring an ammeter help

[MisterCruiser]

Just looking for a wee bit of help wiring in an ammeter, please see attached picture of the gauges wiring diagram.
My question is how to go about attaching the wire to the ignition switch? Is it a spade connectors at the ignition switch?
I thought the ignition switch would just have small skinny wires going to it from a relay or such, I didn't think I could just connect a new big 16mm squared wire from an ammeter to it?

I understand the adding in a wire from starter solenoid to the ammeter on one side. The solenoid usually has a terminal secured with a nut.
And I also get the adding a wire from the gauge to the alternator, the alternator also usually has a stud with a nut to attach to.

However, I'm just wondering about attaching a new wire from the gauge to the ignition switch, how do I physically attach it to the igition switch, will a spade terminal on the switch be ok to handle the amps?
Would anyone happen to have a picture of the ignition switch so I can see the connections?

Also, can someone tell me what the things I have circled in colour are:
Red circled 15 + 30 are referring to ?
Blue circled 58 is referring to ?
Green circled object is ? A fuse?

Also it says use 6mm squared wire for the 30 ammeter and 16mm squared wire for 60 ammeter. Mine is the 60amp version. What is the typical size wires connecting to the battery generally speaking just out of interest? I'm trying to picture what a 18mm wire looks like.

Here's the wiring diagram I'm following which is specific to my VDO gauge.

 

[AdventureWagon]

There's no ignition relay, it's done by the ignition switch. There are actually 2 circuits, AM1 and AM2. Both are switched on in the run position. One gets switched off on the start position. One is for essentials like the engine, one is for other stuff. So it's these two you'll need to measure.

If you are looking for a common point to measure both then you'll have to go to the fusebox under the bonnet. Not sure if a common for the AM1 and AM2 fuse is easily accessible.

 

[Steve Wright]

the problem is you say it is a 60 A ammeter, but most systems today run a 120-200 Amp Alternator, in
the old days they used Dynamo's giving a possible max current of the 60 Amps.

What you need is a modem day version with a shunt that will measure up to say 500 Amps

something like this would do
DC 100V 50A 100A Digital Voltmeter Ammeter Dual LED display Volt Amp Meter Shunt | eBay - [Leaving Land Cruiser Club]

 

[MisterCruiser]

the problem is you say it is a 60 A ammeter, but most systems today run a 120-200 Amp Alternator, in
the old days they used Dynamo's giving a possible max current of the 60 Amps.

What you need is a modem day version with a shunt that will measure up to say 500 Amps

something like this would do
DC 100V 50A 100A Digital Voltmeter Ammeter Dual LED display Volt Amp Meter Shunt | eBay - [Leaving Land Cruiser Club]

Ok, so I bought the wrong ammeter, the one I bought is for older classic / vintage cars then so, typical. Well thanks for pointing that out!

I'm looking at that device on ebay you linked, these are new to me so bear with me here lol
I see it states it's for 50 or 100 amps, will that be ok if the Landcruiser is putting out 120 - 200 amps as you suspect?

I was going to originally buy a 30amp ammeter but when ordering I forgot and ordered the 60 ammeter. But I was then thinking the 60 ammeter would be too high a range, for example the reason I was buying the gauge was to see when an intermittent battery drain was occurring but then I thought a 1 amp drain would be enough to drain a battery over time and I thought this wouldn't show up on the 20amp increments of the 60amp gauge. But as you say the 30 Amp gauge would have been even more useless.

In the attached pic which is from your ebay link, what would be the equivalent of the light bulb in my specific install?
And what is the "shunt" wired to?

And will a shunt type device like the one you linked be able to register a small 1 amp battery drain?

 

[Steve Wright]

To be honest that was just a example but the 100 A version is poss a bit low as depends on what the starter
draws, but when I had one I connected to the battery negative and it would measure every thing but I had the
500 A one.
But to be honest I don't think doing it that way is not the best way, all you need is a digital Multimeter ideally
that will read 20 amps and test all circuits one at a time. Its long drawn out testing but more effective

 

[karl2000]

How intermittent is the battery drain? Personally I'd use an amp clamp to measure the current and see if there's any cause for concern; then if you need to investigate further do a voltage drop test across all the fuses until you find the unexpected load. Doing it that way you don't need to disturb any wiring as nothing needs to be connected inline - you don't even have to use current on your multimeter.

 

[MisterCruiser]

I misunderstood the type and function that the 60 amp ammeter I purchased would be of use.

Instead of disconnecting the negative battery cable and measuring with a multimeter the amps between the negative post and the negative cable end I thought I could just install an ammeter that I could check in on every so often when the vehicle is parked and see by looking at the gauge if the current draw was present at that moment in time and if so then I'd disconnect the negative cable and start pulling fuses.

I just thought it would be a nice handy practical way of catching the problem when it was present. Is there a way to do what I describe?

Well I guess there is, using an amp clamp as Karl2000 describes, just involves opening the bonnet every so often but probably the most practical solution yet.
It's just handy trying to catch the problem this way as I can check it often when the vehicle is parked at the weekends as I go about doing other stuff too. It'd just be handier if I could just glance in at a gauge I though.

Cheers for the tips, I'll dig out my amp clamp meter.

 

[AdventureWagon]

Unless the battery drain is significant (amps) it will probably not show up on a clamp meter or a high current meter like you had originally. You could use a multimeter in current mode (as long as you keep the car off) in series with the battery terminals.

If you can reliably reproduce or predict the drain then measuring voltage drop across fuses is a good way to narrow down the source.

 

[karl2000]

A lot of clamp meters can measure milliamps ok I think

 

[AdventureWagon]

Ah fair enough, milliamps should let you see drain easily.