Ignition Key Switch

[element]

This year has been unkind to me in the automotive sense. First my old Berlingo needed its rear axle replaced then it blew its head gasket, then my wife's Fabia timing chain stretched.. The Marlin arrived late November and its mechanical and electrical restoration has occupied most of my spare time since. Now the key switch has broken to bits.



Hanging down under the key switch is the rear section that fell off this morning with 2 copper terminals falling out together with wee tiny springs. A few months ago the switch wouldn't operate the starter motor so I rewired a separate flick switch on the dash for that. However now the key switch won't even turn the ignition system on. If I were to be able to id the key switch (probably Marina or Ital) and get a reasonable replacement I'd have to remove the dash completely to get at the two bolts that hold the old one together (they screw in vertically downwards from the top either side of the steering column).

Given that I plan to put it off road in the garage for the winter when I'll take on a few major projects, I'm looking for a short term solution to this current problem.



There are 4 wires that attach to the rear of the switch body; Brown, green/white, red/white and white. I need to somehow fit a new key switch to the car and connect up the wires in the right order. Something like this would probably do -

http://www.ebay.co.uk/itm/13H337-31973-ignition-switch-lock-and-keys-CLASSIC-AUSTIN-MORRIS-MINI-MG-Midget-/231315151789?hash=item35db751bad:g:dwYAAOxyUrZS4lZt

However it appears to have 5 connections and not 4...

Your thoughts...?

[scott h]

Re: Ignition Key Switch

Have a look at durite.co.uk. They have around 10 different ignition key switches.

[stevejgreen]

Re: Ignition Key Switch

That switch has three positions, off, ignition and start, the only reason it has five spade terminals is because some are doubled up for ease of wiring. Look at the Ebay pictures.

[dcunn]

Re: Ignition Key Switch

As SG says. That sort of switch will be fine for now, then talk to me in 2 weeks time (I'm on hols tomorrow) when I'm back again.
I have spares on the shelf, some are NOS, and some of them even have keys. My contact details are in Pitstop.

Rgds Dave Cunnington

PS ................... and please remind me again which car is yours

[element]

Re: Ignition Key Switch

The problem I have atm is that I don't know which wires are to go to which connectors on the rear of such a key switch. This one at least shows/supplies a wiring diagram which would help to some degree:

http://www.ebay.co.uk/itm/281862217437?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I have 4 wires; would it be correct in principle that by turning the ignition on, the 4 are linked together through the action of the switch?
I don't require a '2 stage' ignition switch as I already have the starter connected to another switch; just ignition.

ps Dave - It is a Roadster lwb, marina ignition, suspension, brakes etc

[stevejgreen]

Re: Ignition Key Switch

Colour codes on a Marina and a Triumph roadster follow BS-AU7. Lucas pattern. Worth looking up for future reference.

[stevejgreen]

Re: Ignition Key Switch

The problem I have atm is that I don't know which wires are to go to which connectors on the rear of such a key switch. This one at least shows/supplies a wiring diagram which would help to some degree:

http://www.ebay.co.uk/itm/281862217437?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I have 4 wires; would it be correct in principle that by turning the ignition on, the 4 are linked together through the action of the switch?
I don't require a '2 stage' ignition switch as I already have the starter connected to another switch; just ignition.

Which raises the question, how did you wire in the starter switch. You don't want to end up with uninsulated wires dangling free.

The diagram of the first switch was reasonably clear. There is a sequence, no connection, connection to the ignition circuit and ancillaries, and in the last momentary position, connection to the ignition and ancilleries is maintained and the starter motor energised till you release the key.

I do not have a column switch, I have a simple on/off ignition key switch, then a separate push button starter.
It's the direct equivalent of a three position switch. Off, ignition, start.

[stevejgreen]

Re: Ignition Key Switch

The problem I have atm is that I don't know which wires are to go to which connectors on the rear of such a key switch. This one at least shows/supplies a wiring diagram which would help to some degree:

http://www.ebay.co.uk/itm/2818622174...%3AMEBIDX%3AIT

I have 4 wires; would it be correct in principle that by turning the ignition on, the 4 are linked together through the action of the switch?
I don't require a '2 stage' ignition switch as I already have the starter connected to another switch; just ignition.

ps Dave - It is a Roadster lwb, marina ignition, suspension, brakes etc

That's got identical connections, 5 spades, three terminals as the other one you posted.

[b_caswell]

Re: Ignition Key Switch

Brown is live feed
White is ignition
Red/White is starter solenoid
Light green/White feed to heater motor.

You could hot wire the Brown to the white and then with the ignition on you could jump brown to Red/white to start the car. But make sure you have released the steering lock before driving off.

[element]

Re: Ignition Key Switch

Ok I think I have a plan now; I realized the wires were the the ones from the marina & have the marina haynes book so looked the wiring diagram up and its the same as you say. A few months ago I wired in a starter flick switch by taking a spur off the solenoid wire from the key switch (I managed to figure out the correct wire) and left the original one still intact to the key switch. All my rewired connections (wipers, washers, starter etc) are wrapped with heat shrink tube and sealed up so there are no bare wires present anywhere. The current key switch still allows the key to insert & turn & thus release the steering lock, so even if I do fit another ignition key switch, I'll still have to retain the 'dead' one to be able to get by the steering lock.
This winter I'll have to hunt out another ignition key switch assembly which will fit around the steering lock and overhaul it all completely. I was going to remove the dash anyway & replace it with a nice wooden one; bt that's some months away yet.

[Alan c]

Re: Ignition Key Switch

why not upgrade to push button starter with a electronic key fob for security

[HairyDave]

Re: Ignition Key Switch

My 1800TC came with an 'Anti Run On' solenoid which bleeds air into the inlet manifold we the engine is turned off also a two terminal oil pressure switch n/o & n/c. But for this to function it should have had a Slate coloured extra wire from the ignition switch to the ARV relay. Mine didn't so the AV was non functional.

[stevejgreen]

Re: Ignition Key Switch

As far as I recall an Anti Run On Valve was not a UK Marina original part, but it was used on other vehicles like the Classic Mini and MGB so is a fairly easy mod.
The idea was to vent the intake manifold, reducing the vacuum abruptly when the engine was turned off, preventing more fuel being drawn through the carburettors into a hot engine where it could ignite. As HairyDave says, the Anti Run On Valve is controlled, rather crudely, by the oil pressure switch, the theory being that oil pressure will exist for a second or two after the ignition is turned off, and the engine stops rotating, so venting the manifold briefly.
The principle of operation means that the Valve, when unpowered, is open to atmosphere through a gauze filter, but with the ignition on, the Valve is closed.
Certainly if your engine is prone to overheating or the cylinder head is in dire need of decokeing you will suffer from run-on especially if timing and mixture are not set at the optimum.

[HairyDave]

Re: Ignition Key Switch

I found this weird ARV thing in the Roadster's engine room. I got info from a Haynes Marina 1800 manual. It was fitted to B series with all the environmental gubbins that mine hasn't got. The ARV is normally shut. The oil pressure switch is normal open. With the engine running the oil pressure closes the switch but there is no power to it. When the engine is turned off the ARV is energised by a live wire from the ignition via a relay until the oil pressure drops and opens the oil pressure switch allowing the ARV to close. Mine doesn't seem to need it. Confused? You should be. My post was just to explain what a spare wire on your ignition switch might have been for. Stuart Miles 0751762650. breaks Marinas , I have bought bits from him. He is sometimes a bit slow posting but they do arrive. Good luck, Dave
PS sometimes my keboard msses letters and I miss them too