What "Switch" in 2.6 Litre Engine - 2A

[Lionelgee]

Hello All,

Could someone please identify an unknown "switch" and describe what its function was?

I have one fully functioning 2.6 litre six cylinder motor out of a 2A, and a number of the same type of motors in the Series 3 vehicles. I noticed that there is a plate with a male bayonet fitting located on the head towards the top radiator hose mounting. The 2a engine has the fitting while my Series 3 engines do not - they just have a blank plate located in the same place.

I looked at my 1975 Series 3 Parts Catalogue and it states there is a "switch" Part Number 545010. There is no mention of what type of "switch" it is. There is also a note numbered with a circle of 2 that suggests that this switch was discontinued and replaced with the blank plate from November 1972 onwards.


So what was the switch and what role does it perform?

The main reason for finding this out is that the Series 2A motor with this switch is hooked up to an electronic ignition system and there are wires running from the black box that is connected with the choke cable that run to this unknown switch.

I am thinking of swapping this electronic system over to one of my Series 3 engines and it would be handy to know if this "switch" should come across in the conversion?

By the way the fourth attachment shows the black rectangular box that sits on the choke cable. The Parts Catalogue identifies this as Part Number 563318 and it is labelled - you guessed it "switch"! Can someone please let me know what this rectangular "switch" with two fittings on it is and what role does it play?


I have attached photographs that identify the bits and bobs. Thank you.

Kind Regards
Lionel

[Lotz-A-Landies]

I'll have to check the SIIA wiring diagrams when I get home, but from memory it is the choke warning light (thermocouple) switch.

When you pulled out the choke cable a switch (your image 4) was closed, a wire continued from this to the switch on the engine. When the engine came up to operating temp the thermocouple switch closed completed the circuit and the amber light on the dash illuminated.

Diana

[rover-56]

Lionel, the switch in the head is a water temperature sender, some models have a conventional threaded sender in a tapped hole on the rhs behind and below the one in your pic. The one in the cable switches the choke warning light as Diana said.

Terry

[PhilipA]

Yep, same in early Rangies. AFAIR , the light comes on at 60C or so to remind you to push the choke button in.
Regards Philip A

[JDNSW]

The cold start* warning system on all Series 1.2.2a and, I think, some 3, comprises three bits - a thermal switch on the head, which is what you refer to, a switch on the cold start control cable, and an orange warning light on the dash, plus the wiring between them.

It is intended to come on when the "choke" is pulled out and the engine reaches a temperature that allows it to run with it pushed in.

John

*Rover used the term "cold start" rather than "choke", because the Solex carburettors, used until the mid sixties, did not have a cold start device that could strictly be called a choke - it does not restrict air, but adds petrol.

[Lotz-A-Landies]

Hi Lionel

Just to hyjack your thread a little.

If you are using a SIIa 6cyl in your Army SIII there are a couple of things to consider.

The Army units didn't use the SU carby but a Stromberg CDI.

The Army ones used a Bosch dissy the civvy ones a Lucas.

The civilian lifting brackets only have a small slot, the army ones had a large hole through which you could sling a chain.

If you want people to overlook the origins of your engine, it may be worthwhile swapping over these bits. ;)

Diana

[Lionelgee]

Hi Lionel

Just to hyjack your thread a little.

If you are using a SIIa 6cyl in your Army SIII there are a couple of things to consider.

The Army units didn't use the SU carby but a Stromberg CDI.

The Army ones used a Bosch dissy the civvy ones a Lucas.

The civilian lifting brackets only have a small slot, the army ones had a large hole through which you could sling a chain.

If you want people to overlook the origins of your engine, it may be worthwhile swapping over these bits. ;)

Diana

Hello Diana,

I have a totally civilian Series 3 ute that was originally fitted with a six cylinder motor. I bought it with a Holden 202 motor. The previous owner said that it had started to jump out of top gear when going down hill or cruising along flats - not under load. From what little I know about the Holden conversions this signals alignment issues and a box with a limited lifespan.

One option I have is to take out the Holden 202 and the gearbox and replace it with the gearbox from my Series 3 stock diesel and mate it to the Series 2A engine. The Holden conversion was never approved by Queensland Department of Transport although the conversion was done professionally in Maryborough. This means there are no blue plates fitted to it.

Carburettor wise: the 2A has a Zenith Stromberg CD 175 s. My 1978 ex-Army Land Rovers have the CD 175. My 1980 FFR has a CD 175 2.

Sparks: Yes all the army stuff is Bosch.

The 2A is all Lucas and other electronic conversion parts.

Kind Regards
Lionel

[Lionelgee]

The cold start* warning system on all Series 1.2.2a and, I think, some 3, comprises three bits - a thermal switch on the head, which is what you refer to, a switch on the cold start control cable, and an orange warning light on the dash, plus the wiring between them.

It is intended to come on when the "choke" is pulled out and the engine reaches a temperature that allows it to run with it pushed in.

John

*Rover used the term "cold start" rather than "choke", because the Solex carburettors, used until the mid sixties, did not have a cold start device that could strictly be called a choke - it does not restrict air, but adds petrol.

Hello John,

Thank you for the reply. So the cold start = choke warning light is similar to what I may remember the EH Holden used to have. It was with a cluster of three lights. The other two were too late lights - once the lights came on your engine was just about history!

Kind Regards
Lionel

[Lionelgee]

Lionel, the switch in the head is a water temperature sender, some models have a conventional threaded sender in a tapped hole on the rhs behind and below the one in your pic. The one in the cable switches the choke warning light as Diana said.

Terry


G'day Terry,

From your description I might have tracked down the site of the "conventional threaded sender" located on the block below where the plate is? The photographs of the site are on a Series 3 block made in 1978.

The other photographs show different angles of the Cold Start switch that was taken off the 2A motor attached to the CD 175 s carburettor.

This was done to eliminate the carburettor as a possible cause of the Series 3 motor not starting. I knew the 2A engine's carburettor worked well and made the engine purr. It turns out the Series 3 CD 175 had a very seized main piston. I have since got this carburettor sorted out and running on the 2A engine, so it is going back on the Series 3. The 2A's carburettor will be going back on the 2A engine again to keep it original to how it first arrived here.

Kind Regards
Lionel

[Lotz-A-Landies]

Hello Diana,

I have a totally civilian Series 3 ute that was originally fitted with a six cylinder motor. I bought it with a Holden 202 motor. The previous owner said that it had started to jump out of top gear when going down hill or cruising along flats - not under load. From what little I know about the Holden conversions this signals alignment issues and a box with a limited lifespan.

One option I have is to take out the Holden 202 and the gearbox and replace it with the gearbox from my Series 3 stock diesel and mate it to the Series 2A engine. The Holden conversion was never approved by Queensland Department of Transport although the conversion was done professionally in Maryborough. This means there are no blue plates fitted to it.

<snip>

Kind Regards
LionelHi Lionel

A series box slipping out of top may actually be the 3rd/4th synchro cones, the detent springs around them or wear on the bronze bush supporting 3rd gear +/- too much end fload on the thrust washer between 2nd and third. As you say it could have been caused by an out of alignment adaptor.

The diesel gearbox will need a SIII 6cyl bellhousing (but you likely have one of those on the dodgy box behind the 202). Otherwise I have a spare.

Diana

[Lionelgee]

The diesel gearbox will need a SIII 6cyl bellhousing (but you likely have one of those on the dodgy box behind the 202). Otherwise I have a spare. Diana

Hello Diana,

Thank you for the offer of the bellhousing for a six cylinder.

Yes, there is one on the back of the Holden 202. Luckily I have a couple more up my sleeve too.

There are benefits of living on acreage; storage space for one or two :Rolling:spare parts vehicles. :)

Kind Regards
Lionel

[Lotz-A-Landies]

A bit like sharing cookey's chook shed!

[rover-56]

Sorry, I wasn't very clear in my post and I am probably confusing people. The sensor with the 3 mounting screws is the switch associated with the cold start warning light. The other one lower down is the normal sender which drives the temperature gauge.

Looks like you have a bit of fun parts swapping coming up:)

Cheers,
Terry

[Lionelgee]

Sorry, I wasn't very clear in my post and I am probably confusing people. The sensor with the 3 mounting screws is the switch associated with the cold start warning light. The other one lower down is the normal sender which drives the temperature gauge.

Looks like you have a bit of fun parts swapping coming up:)

Cheers,
Terry


G'day Terry,

Okay the 3 mounting screws is the cold start one on the 2A.

My 1975 Parts Catalogue states that Part Number 545010 was superseded in November 1972 onwards.

Was this switch replaced by something else or just eliminated altogether? If this is the case where does one of the wires from the thermoswitch mounted on the choke cable (cold start) connect to on the Series 3? I have the thermoswitch but it is not wired to anything on any of the Series 3 motors I have.

The page I scanned and posted earlier does have part number 560794; this is identified as "water temperature transmitter" that looks like it in the diagram goes near the thermostat. I could be reading the diagram incorrectly too. Is this the replacement for the switch under three screw plate in the 2A "from November 1972 onwards "or were they always there anyway - even with Part Number 545010 hooked up?

It all depends on my level of masochism at the time as to whether I do a complete swap out of the Holden motor. The other option is to use the specially bought dial gauge and my following the instructions to get the replacement gear box alignment right. The link that is posted under "you must read this" sticky note under the Series - Holden Powered site (http://www.aulro.com/afvb/holden-powered-series-land-rovers/133415-before-fitting-holden-engine-check-aligment-first.html). Either way I will replacing the clutch components and getting the flywheel machined - when the money comes to do it that is. This could take a while it seems! I am just taking dolly steps at the moment and using what resources I currently have available. Yes, Terry lots of parts swapping fun ahead :p

Kind Regards
Lionel

[rover-56]

G'day Terry,

Okay the 3 mounting screws is the cold start one on the 2A.

My 1975 Parts Catalogue states that Part Number 545010 was superseded in November 1972 onwards.

Was this switch replaced by something else or just eliminated altogether? If this is the case where does one of the wires from the thermoswitch mounted on the choke cable (cold start) connect to on the Series 3? I have the thermoswitch but it is not wired to anything on any of the Series 3 motors I have.

The page I scanned and posted earlier does have part number 560794; this is identified as "water temperature transmitter" that looks like it in the diagram goes near the thermostat. I could be reading the diagram incorrectly too. Is this the replacement for the switch under three screw plate in the 2A "from November 1972 onwards "or were they always there anyway - even with Part Number 545010 hooked up?

It all depends on my level of masochism at the time as to whether I do a complete swap out of the Holden motor. The other option is to use the specially bought dial gauge and my following the instructions to get the gear box alignment right. The link that is posted under "you must read this" sticky note under the Series 3 Holden Powered site. Either way I will replacing the clutch components and getting the flywheel machined - when the money comes to it that is.

Kind Regards
Lionel
The water temperature transmitter is powered from the gauge and is a variable resistance. The 3 screw one is just a switch which closes on temperature rise, giving voltage from the warning light a path to ground via the cable switch,turning on the warning light. So the sequence is power from ignition to warning light, then to the cable switch, then to the cylinder head switch, and then to ground.
Terry

[Lionelgee]

Hello All,

In the dark and armed with a camera I just went into the paddock and checked my collection of vehicles. I do have a Series 3 that has the little rectangular box mounted on the cold start cable. It does have two wires and they feed directly back through the fire wall.

Apart from the inner cable connecting to the carburettor; unlike the 2A motor, there is absolutely no contact with the head or the engine block.

I could not work out the colour of the trace on the black wire between the camera flash and the caked on grot, so I will check them out tomorrow morning and follow the circuit back. It will, from all suggestions, go back to the "cold start" warning light in the instrument cluster.

It is all very interesting ;) One thing about old Land Rovers, one never stops learning about them and their quirks.

PS: I checked with the "Green Bible" the Land Rover Series 3 Repair and Operation Manual (ed. 4) and it shows how there is just a white wire with a blue trace and a black wire with no colour trace on it. The part in the schematic drawing is Part 41, described as "switch choke". The circuit has the white wire with the blue trace going back to Part 35, "warning light - choke". The other side of Part 41; the black wire goes to an earth point - somewhere?

Kind Regards
Lionel

[PhilipA]

AFAIR The black wire goes to the triangular switch which earths when it gets hot.
On an RRC there is a switch also at the choke knob. When you pull out the choke, this completes a circuit to the triangular switch which is open circuit until it warms up. It then grounds and Voila a red light comes on.
Regards Philip A

[Lionelgee]

Hello All,

JC on a bike!!! I just did some research about the availability of the two "switches". The 2A and early Series 3 three screw switch (Part Number 545010) is worth £69.56, yes that is UK Pounds!

The other rectangular switch mounted directly on the choke has changed from Part Number 563318 is now known as Part Number RTC5816 and it is worth a mere £25.18 exc. VAT

That is a fair bit of money to let people know that the choke is on :o

Kind Regards
Lionel