GT6 mk3 ignition switch wiring 4,5 or 6 connections?

[BestyA]

My GT6 has previously had the steering column changed to a Dolomite (by the PO), so the ignition and key position is in the "usual" position at the top of the column. 

I like the inconvenience of the original GT6 ignition position (and want to revert to as much as original as possible) and have bought off ebay an original steering column with the key position down low (between the knees). 

The current (Dolomite) ignition has 6 connections on the rear of the switch whereas the second hand one (from ebay) has 4 connections. Looking at the ones supplied by Rimmers there are 5 coonections. The wiring diagram says 6.

Questions are:

• Can I somehow use the 4 connection one I have
• Will the 5 connector version from Rimmer do the job
• Do I need a 6 connection version (and where do I get one)
• Also can I get a connection to the radio with any of these versions - on when key in position 1 (if that makes sense)

 

[dougbgt6]

I've replaced the  original switch on my GT6 as the innards failed, I got the 5 way one. That small screw locks in the switch and there's a locating slot, the switch pops out easily. The wiring in the first picture looks scary  there's broken insulation, it needs replacing. However,  I wonder what's beyond the black tape, top right, hopefully the original correctly coloured wires? Which should make re-connection clearer.

Doug.

[BestyA]

26 minutes ago, dougbgt6 said:

I've replaced the  original switch on my GT6 as the innards failed, I got the 5 way one. That small screw locks in the switch and there's a locating slot, the switch pops out easily. The wiring in the first picture looks scary  there's broken insulation, it needs replacing. However,  I wonder what's beyond the black tape, top right, hopefully the original correctly coloured wires? Which should make re-connection clearer.

Doug.

The wiring is scary, I have ripped out and replaced quite a bit of domestic wiring so far (and just found some more!) It's all been replaced along with a new 10 way fusebox, relays for the lights and rear heated windscreen.

The original colours are there as there are a number of soldered splices under the dashboard, my guess is that the 5 way combines 4 and 2 on the 6 way connector?

[dougbgt6]

Yes 4 & 2 sounds right.

I've put in a 10 way fuse box, as long as you keep to the red, purple and green that feed the original 3 fuses in their groups, nothing nothing else needs to change. I've also got relays for the lights, but not the rear screen, it rarely gets iced up these days .

Doug

[ChrisJB]

My GT6 Mk3 has four connections, numbered 1,2,3,5 on the Lucas switch (Pt no 1575A) as per the photo of the switch module in the original post.  The Haynes Manual wiring diagram also shows a 5th connector numbered 6 that controls an anti run-on valve, this is not fitted to UK cars? The diagram states "Not all items are fitted to all models". 

The Haynes wiring diagram also shows connectors 4 and 2 on the switch connected together on the switch confirming Doug's post.

[BestyA]

10 hours ago, ChrisJB said:

My GT6 Mk3 has four connections, numbered 1,2,3,5 on the Lucas switch (Pt no 1575A) as per the photo of the switch module in the original post.  The Haynes Manual wiring diagram also shows a 5th connector numbered 6 that controls an anti run-on valve, this is not fitted to UK cars? The diagram states "Not all items are fitted to all models". 

The Haynes wiring diagram also shows connectors 4 and 2 on the switch connected together on the switch confirming Doug's post.

That's helpful,I will see whether I can get the 4 to work.

[ChrisJB]

Hi,

A few further thoughts- looking at your photo of the Dolomite switch is the extra terminal at the top of the switch connected to the thick brown wire under the heat shrink?  In this case it may be irrelevant if you change the switch.  Check the operation of your current switch, as you turn the key note down which terminals are connected to the battery (this should be the brown wire). 

The standard four terminals should connected as follows for a UK car (original loom colours and a Mk3):

Terminal 1: White/ Red wire- Starter Solenoid

Terminal 2: Brown- feed wire from battery

Terminal 3: White wire(s)- Ignition and other circuits fed from the ignition.

Terminal 4: White/ pink wire- Auxiliary circuits, Heater fan and radio if installed.  This is the connection for the radio- on the original wiring loom if I remember correctly there is a spare bullet connector in the loom that can be used for the radio if not fitted.

The attached picture shows the operation of the 4 position switch.

Chris

[Jim-GT6]

As the thread is on ignition switch function, can I ask a related question?

My ignition has failed. There is no spring back of the key from the starter position, and nothing comes on on the dash. I pulled the ignition switch off the back of the lock assembly (it just slid off - screws may be missing) and turned the switch with a screwdriver. Starts fine. No issue. The switch itself does not spring back, so starter continues until you back it off a few degrees. 
My question is which one has failed? The key barrel assembly or the switch? Which one provides the ‘spring’ back from starter position? The switch or the lock barrel? If it’s the switch that should be spung, then a new switch should fix it I hope.

[BestyA]

Hi Jim, just tried it and it is the switch that gives it the spring.

[Jim-GT6]

Fabulous!! Thank you. A 10 min job for £35 instead of a really tricky one for £80. Thanks so much for investigating. 🙏