Push Button Start Switch
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Push Button Start Switch
Has anyone thought about changing the start switch to a push button switch. The way the key goes in is so awkward, especially with my big hands.
Here is a similar discussion on the MG forum:
https://www.mgexp.com/forum/mga-forum.2 ... n.4174888/
Here is a similar discussion on the MG forum:
https://www.mgexp.com/forum/mga-forum.2 ... n.4174888/
- AndrewWebber
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Re: Push Button Start Switch
I have fitted one in my 'Europa'. I found it failed quickly until I fitted a relay between it and the starter solenoid on the starter motor, it has then been fine since with very little current draw.
Andy
Andy
- Hawaiis0
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Re: Push Button Start Switch
That's how they should be wired. Low current control switching high current relay.AndrewWebber wrote: ↑Tue Oct 29, 2024 17:37I have fitted one in my 'Europa'. I found it failed quickly until I fitted a relay between it and the starter solenoid on the starter motor, it has then been fine since with very little current draw.
Andy

Nothing is fool proof. Fools are clever!
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Re: Push Button Start Switch
I like the idea - I'm so used to pressing a button these days I'm going to be looking for one when the Elite is driveable! There are some nice subtle push buttons available now.
Pete
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Re: Push Button Start Switch
I use the horn push button on my Clan's steering wheel to start the engine. I like this arrangement because for added coolness, the horn button, like the Excel, has the brand logo, which I think is a nice touch for a start button.
Ok, this must at first sound like a stupid idea, but using some basic schoolboy electronic trickery the horn push becomes a dual function button capable of sounding the horn and starting the car! ACBC would approve of the dual functionality I'm sure.
The normal horn push button is wired to a DIY electronic 'timed changeover' circuit that temporarily connects the horn push button to the starter motor relay for just a few seconds after the car ignition is armed via a separate dash switch. After the set time ( about 30 secs in my case using a 555 timer chip, capacitor, and a potentiometer to set the time period), the circuit's changeover relay reconnects the horn push button back to the normal horn circuit.
I found 'armed for 30 sec' provides enough time for a second or third crank if the engine doesn't start first time. The capacitor and potentiometer values provide the range of settable time available.
For safety, the horn push button remains connected to the horn circuit at all times during driving, only switching to the starter motor relay after killing the ignition to stop the engine. When the ignition is re-armed it becomes a start push button again for the set time (30 sec in my case).
For the Clan, the ignition is armed via a classic Lucas lighting pull switch on the dash (I don't use a key switch), but you could use a key switch to arm the ignition for security if you wish. The Clan's steering wheel is removable, so the start button/horn button goes with me when leaving the car, hence I don't need a key switch!
Look up 555 timer circuits online for circuit plans. They are pretty simple to make.
NB. As with all car electronics, the earth and 12v supplies must be as clean as possible to prevent spikes and possible re-arming whilst driving. So a separate, direct, non-shared 12v battery supply and direct non-shared chassis earth is needed as would be necessary if you fitted an aftermarket EFI ECU to your classic Lotus.
Ok, this must at first sound like a stupid idea, but using some basic schoolboy electronic trickery the horn push becomes a dual function button capable of sounding the horn and starting the car! ACBC would approve of the dual functionality I'm sure.
The normal horn push button is wired to a DIY electronic 'timed changeover' circuit that temporarily connects the horn push button to the starter motor relay for just a few seconds after the car ignition is armed via a separate dash switch. After the set time ( about 30 secs in my case using a 555 timer chip, capacitor, and a potentiometer to set the time period), the circuit's changeover relay reconnects the horn push button back to the normal horn circuit.
I found 'armed for 30 sec' provides enough time for a second or third crank if the engine doesn't start first time. The capacitor and potentiometer values provide the range of settable time available.
For safety, the horn push button remains connected to the horn circuit at all times during driving, only switching to the starter motor relay after killing the ignition to stop the engine. When the ignition is re-armed it becomes a start push button again for the set time (30 sec in my case).
For the Clan, the ignition is armed via a classic Lucas lighting pull switch on the dash (I don't use a key switch), but you could use a key switch to arm the ignition for security if you wish. The Clan's steering wheel is removable, so the start button/horn button goes with me when leaving the car, hence I don't need a key switch!
Look up 555 timer circuits online for circuit plans. They are pretty simple to make.
NB. As with all car electronics, the earth and 12v supplies must be as clean as possible to prevent spikes and possible re-arming whilst driving. So a separate, direct, non-shared 12v battery supply and direct non-shared chassis earth is needed as would be necessary if you fitted an aftermarket EFI ECU to your classic Lotus.
Last edited by Lotus-e-Clan on Tue Oct 29, 2024 20:50, edited 2 times in total.
Peter K
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Re: Push Button Start Switch
Not all "developments" are good. Our nc mx5 had a conventional key, the nd mx5 we now have is a push button....its a pita. If you are sat in the car with the engine off double pushers required to open/ close windows, turn the radio on without the engine running, it complains if you then try to exit the car, it also puts the daylight running lights on if you do this further running the battery down and other weird things happen. If the key fob battery goes flat you have to use the key built into the fob to open the door but the alarm goes off until you hold the fob up to the push button until the proximity sensor eventually decides its nearby and then the alarm shuts off and then you can start it with the fob next to the button......arrrgggggg !
Fashion I suppose, but give me a key any day.
Did I mention its a pita.
Bash
Makes me want to do a basil fawlty with a big branch.
Fashion I suppose, but give me a key any day.
Did I mention its a pita.
Bash
Makes me want to do a basil fawlty with a big branch.
Two things are infinite: the universe and human stupidity; and I'm not sure about the universe.
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Re: Push Button Start Switch
Bash - that's because your Mazda push button is on the CAN bus - just using a push button to activate a relay won't be so troublesome.
I love your idea of using the horn push Peter - The Elite doesn't have one at the moment - it's on the stalk - but I'll look into fitting one to the Momo steering wheel centre. More project creep!! I like being able to steel good ideas!!
Pete
I love your idea of using the horn push Peter - The Elite doesn't have one at the moment - it's on the stalk - but I'll look into fitting one to the Momo steering wheel centre. More project creep!! I like being able to steel good ideas!!

Pete
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Re: Push Button Start Switch
Note, this is when the stuff is working as intended, not 20 years down the line when (not if) a connection corrodes or the computer (keyed to the car) corruptsbash wrote: ↑Tue Oct 29, 2024 20:39Not all "developments" are good. Our nc mx5 had a conventional key, the nd mx5 we now have is a push button....its a pita. If you are sat in the car with the engine off double pushers required to open/ close windows, turn the radio on without the engine running, it complains if you then try to exit the car, it also puts the daylight running lights on if you do this further running the battery down and other weird things happen. If the key fob battery goes flat you have to use the key built into the fob to open the door but the alarm goes off until you hold the fob up to the push button until the proximity sensor eventually decides its nearby and then the alarm shuts off and then you can start it with the fob next to the button......arrrgggggg !
Fashion I suppose, but give me a key any day.
Did I mention its a pita.

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Re: Push Button Start Switch
Very true.
Another annoyance that was rectified on later cars is that there is no boot release in the car and it wont let you use the fob unless you are outside the car. Conveniently there is a secret button under the rear bumper where you will get dirty though.
Everything else about the car is frankly brilliant but letting a child computer toy expert loose on this was a mistake.
Bash
Another annoyance that was rectified on later cars is that there is no boot release in the car and it wont let you use the fob unless you are outside the car. Conveniently there is a secret button under the rear bumper where you will get dirty though.
Everything else about the car is frankly brilliant but letting a child computer toy expert loose on this was a mistake.
Bash
Two things are infinite: the universe and human stupidity; and I'm not sure about the universe.
- pistolpete
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Re: Push Button Start Switch
I clearly have just old cars, no buttons but love the idea. so how does not having a key work with the steering lock, I sort of assumed you had to have a key and a button, in which case the pain in the A... s of a key remains
- Lotus-e-Clan
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Re: Push Button Start Switch
Good point about the steering lock! Clan hasn't got one, but there's a possible option that might appeal.pistolpete wrote: ↑Wed Oct 30, 2024 17:46I clearly have just old cars, no buttons but love the idea. so how does not having a key work with the steering lock, I sort of assumed you had to have a key and a button, in which case the pain in the A... s of a key remains
Embed the key head into a pretty rotary aluminium knob so it doesn't look like a key at all. The modified rotary key knob is then left in place and only removed when secondary/additional security is needed. Transfer the ignition wiring to a stealth switch elsewhere.
So the lazy, low security, startup protocol with the fancy modified rotary keyknob left in the de-wired column lock switch in position 1 ( steering lock off therefore) would be:
1. Open the car with remote.
2. Flick stealth ignition switch to on.
3. Press horn push to start car.
If left in a vulnerable location, take the rotary key knob out of the ignition/column lock. Otherwise leave it in the column and lock the car with the remote. No one normal will realise the key is in the car.
Example in my SMART.
Peter K
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Re: Push Button Start Switch
Peter - you obviously spend as much time as I do pondering these things!
. Another great idea about the steering lock.
Pete

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Re: Push Button Start Switch
Yeah, a lifetime in problem-solving vocations means a solution equals happiness, and an unsolved problem equals 24/7 misery and torment.Pete Boole wrote: ↑Wed Oct 30, 2024 22:50Peter - you obviously spend as much time as I do pondering these things!. Another great idea about the steering lock.
Pete
It has plenty of downsides. l take a puzzle book to the loo. Can't get off until the puzzle is complete. But age has slowed my brain and puzzles seem harder, so now I have a permanent impression of the toilet seat on my backside.
I guess the rotary key knob/start button idea could also be a decent alternative to replacing the commonly found worn ignition switch too.
Peter K
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Re: Push Button Start Switch
Ooh yeah, forgot to add that for the dual function horn push, a green LED lights for the duration of the set time the starter is armed (30 secs). Easy to add an LED to a 555 timer circuit. Can have a different coloured LED lit for the active horn period too if required.
Saves the embarrassment of sounding the horn at 31 secs when starting the car!
Saves the embarrassment of sounding the horn at 31 secs when starting the car!
Peter K
- DavidOliver
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Re: Push Button Start Switch
I recently had a Cobra Alarm failure rendering the car unable to start.
I rigged directly Ignition and Starter Solenoid cables (note the solenoid does not draw a high current, it is not the Starter Motor itself so relays IMO are not necessary for the solenoid), and later included a push button for the starter, located under the dash.
I have now gone back to original with a new ignition switch mainly as here in Spain a car designated officially as Historic is not allowed any modifications from original. I do not want an over zealous inspector failing the bi-anual ITV (MOT)
Dave the cog.
I rigged directly Ignition and Starter Solenoid cables (note the solenoid does not draw a high current, it is not the Starter Motor itself so relays IMO are not necessary for the solenoid), and later included a push button for the starter, located under the dash.
I have now gone back to original with a new ignition switch mainly as here in Spain a car designated officially as Historic is not allowed any modifications from original. I do not want an over zealous inspector failing the bi-anual ITV (MOT)
Dave the cog.