Help with S2a electrics and S3 diesel engine/alternator combination

[Cap]

After reading a tonne of stuff online from a lot of different forums including the AULRO brains trust, I now believe that when it comes to electrics I just 'dont get it'. As a result, I do have a set of questions that I would like SIMPLE LAYMANS (if possible) answers to please.

Contraints:
1) 1963 S2a with original wiring including voltage regulator and ammeter on instrument cluster (+tive earth setup)

2) Engine is 2.25 diesel 3brg (told from an S3) with alternator, thick cable going from rear of alternator to +tive battery terminal (negative earth setup).

Questions:
Alternator would be going to +tive on battery terminal, body of alternator going to chassis ground (both leads already on alternator) - is this correct?

Voltage regulator - the big unit bolted to the bulkhead near the steering column. My understanding is this is purely to provide an 'average' 10v to the fuel and ammeter gauges (not sure about temp gauge) - is this correct?

Given the alternator pumps out up to 14v to keep the battery charged, the voltage regulator is still required for the gauges to operate accurately? - is this correct?

Ammeter - a measure of current draw?, however voltmeter preferred so can disconnect this and keep on dash to retain original look. What do I do with the two connectors?

As the wiring is +tive earth, I need to convert to -tive earth due to alternator. No other changes to the wiring required if the ammeter is disconnected? Any thing else I need to know?

[goingbush]

<snip>

Questions:
Alternator would be going to +tive on battery terminal, body of alternator going to chassis ground (both leads already on alternator) - is this correct?

correct




Voltage regulator - the big unit bolted to the bulkhead near the steering column. My understanding is this is purely to provide an 'average' 10v to the fuel and ammeter gauges (not sure about temp gauge) - is this correct?

NO, the Regulator is redundant, not required.
Ammeter now redundant ,

Temp & fuel gauge use a voltage stabiliser (often incorrectly referred to as a regulator) , a small thing behind the dash.




Given the alternator pumps out up to 14v to keep the battery charged, the voltage regulator is still required for the gauges to operate accurately? - is this correct?

Incorrect - see above.




Ammeter - a measure of current draw?, however voltmeter preferred so can disconnect this and keep on dash to retain original look. What do I do with the two connectors?

connect them together & insulate.




As the wiring is +tive earth, I need to convert to -tive earth due to alternator. No other changes to the wiring required if the ammeter is disconnected? Any thing else I need to know?

You might need to get a new flash can and find a voltage stabiliser for your gauges.

[goingbush]

Dont forger the Alternator light , probably use your old generator light if its not earthed to the dash , if you cant follow this diagram let me know & I'll highlight the bits you need. Its about as simple as it gets.

https://atko.org/pix/2012-05-29%20(3).jpg

[Cap]

NO, the Regulator is redundant, not required.
Ammeter now redundant ,

Temp & fuel gauge use a voltage stabiliser (often incorrectly referred to as a regulator) , a small thing behind the dash.


Thanks. When i pulled the dash for both the 88 and 109 2a the only unit in there was the cylinder flasher (wiring ran to stalk). I didnt see any other device. So what does the voltage stabiliser look like?

Edit: Does it look like this (http://www.wheels-alive.co.uk/need-to-know-series-no-1-instrument-voltage-stabiliser/), cos I dont have it.


As for the voltage regulator unit, there are a number of wires going into it. What happens with these terminals?

Cheers,

[JDNSW]

More or less, although it can be replaced by a solid state device. In Series 2a (from Suffix 'C' on, it is on the bulkhead behind the instrument cluster, on Series 3 it is on the back of the speedo.

However!

If it has an Ammeter, it left the factory without a voltage stabiliser, as the fuel gauge fitted up to 1967 (Suffix 'B' does not require one, and there is no temperature gauge). Since you discuss the Ammeter, I strongly suspect you will not find a voltage stabiliser.

[Cap]

Thanks. OK just rechecked the dash and yes I made a mistake, no temp gauge as such. Attached is the dash x 2 - grey is the 67 2a, green the 63 2a.

https://farm2.staticflickr.com/1886/30652233518_37ea3d215d_c.jpg

So with no voltage stabiliser, the only thing left is the voltage regulator wires if this is no longer needed. So whats the best way to connect these (bridge them)?

[goingbush]

So with no voltage stabiliser, the only thing left is the voltage regulator wires if this is no longer needed. So whats the best way to connect these (bridge them)?

no you've got both pos and neg there , if you bridge them you will empty the smoke out of the loom, lots of it .

[goingbush]

refer to this diagram. & alternator diagram in above post.

Remove all wires A & A1 from Regulator & join all together.

Remove F - not needed . It wont be thick enough to run to the Alternator & supply 50Amp otherwise you could join it in with A & A1 and use it for Alternator +ve

Remove both D wires and join them together (insulate) and take that D wire from the generator and connect it to the Alternator IND connector .


https://bestharleylinks.info/img/land-rover-series-2a-wiring-diagram-anonymerfo-of-land-rover-2a-wiring-diagram-5.jpg

[Cap]

Started to put the wiring back in after inspection and it will do for now. I found that the loom that goes into the cavity behind the dash cluster has a purple wire plug. This purple wire seems to be used for different purposes on different wiring harnesses. Given its behind the dash, was this wire the feed to interior light (optional) - the two diagrams above show the different uses of this purple wire so wanting to make sure leaving if blank was meant to be as there are no other wires joining to it.

[JohnboyLandy]

Hi Carlos,

As far as I'm aware the only purple wire on a standard s2a / s3 wiring diagram is the stop light, and it's purple with a green trace.

I don't know of any purple behind the dash.

Cheers,
John

[Cap]

Thanks, on further inspection of wiring diagrams there is an optional interior light feed, purpose colour (no trace). I think thats what it is so at this stage ill ignore it.

[Cap]

Getting into the wiring and so far I have been successful in it (ie, no smoke!). The dash cluster all works with both lights and ignition. I think I am getting my head around the wiring diagrams too as I have been able to chase wires to components and its all making sense now.

However, I have come across something that is either weird by design or my misunderstanding. In early 2a diagrams, the starter button wiring is the connector between the battery and the starter... to my dismay I finally realised the the starter button and ignition switch are independent. The means you can crank over a series engine without the ignition on. Firstly, I think this is ridiculous and an issue for diesel owners as you can effectively crank over a diesel (in hot weather where glow plugs may not be needed) and drive away!! On a petrol its different as you have the coil feed from the ignition, which is at least somewhat theft proof.

Am I correct in my thinking that the wiring is meant to be like this? I will be looking at changing the wiring to incorporate the ign key as part of the battery feed to both starter solenoid and glow plugs. Yes I know I can buy the later S3 key, but I still prefer to go with the starter button option.

[JDNSW]

Petrol Landrovers up to the 1967 change to negative earth used a starter switch that was a simple switch in the main battery lead to the starter - i.e. no solenoid. Diesels used a more or less conventional ignition/heater plug/start switch, located below the instrument panel (no ignition switch in the light switch), that directly switched the preheaters and operated the solenoid mounted on the starter.

If you have converted a petrol model to diesel, as you say, you don't want the engine able to be started without the key. The solution is, as you suggest, to use the starter switch to operate the starter solenoid, feeding it (and heater plugs) from the ignition circuit.

The heater plugs must use a relay, as the rotary ignition switch is not designed to carry that much current.

[Cap]

Thanks John, I cant believe I actually rear the wiring diagrams right lol. I will put a relay in for sure (as I will for headlights that have the inbuilt fuse). Also ill be adding fuses to the other wiring that is unfused!

Although looking at this diagram for a S2a Diesel +tive earth, theres not much there either in being able to start it...
148604

[JDNSW]

That wiring diagram, Figure N1-3 in my manual, I have not seen in the flesh - probably Series 1-2 diesel. My very early 2a diesel had the wiring diagram Figure N1-4, with ignition, heater plugs and starter in one switch, and I was not aware of this one. Reflects a more innocent age, I suspect, along with things such as optional door locks.

[Cap]

Its sad to think things have gone the way they are with anti theft devices nowdays. My father told me that when he was in his 20s you could leave the car, garage and house all unlocked and there was never any problems. As you say, back in the day there was no need to consider these issues.

[JDNSW]

Back around 1950, an uncle of mine traded in his Rover 9 touring car (no lock, no side curtains) on an Austin A70. He had been accustomed when doing the weekly shopping in Newcastle to just put stuff on the back seat, never any issues. First time he went shopping in the Austin, after carefully locking the doors, someone broke in and stole his groceries!

Edit - typos

[Cap]

That would be right!!

Update... tonight i managed to wire in a relay that is triggered by the coil wire (being a petrol wire loom) and then power is fed to the buttons - one for the glow plugs, the other the starter solenoid. Only way i could do this was to separate the two wires that are plugged into the switch (for feed into ignition) and have the buttons only powered via the relay.

Tested both buttons and worked as expected, so im pretty chuffed I managed this without smoking the loom up lol. Now i have the starter and glow plus only work when key ignition is on, so no cranking of motor with it!

I also got a 850cca, 95amp battery that fits the tray, with correctly positioned terminals for $224. Happy!