Car Engine start button questions

Forums › Off topic › Car Engine start button questions

1 | 2 | 3 | 4

2584 posts

Uber Geek

Retired Mod

Trusted

Lifetime subscriber

#440988 18-Feb-2011 06:24

My brother has a starter button in his car and from what I have seen he has a second button that enables the starter button. It is a one use deal so each time he wants to start the car he presses the enable button then the starter button which in turn resets the enable button. Have no idea how it is done electrically though.
The other simple answer as I see it. Have the button on the right side of the steering wheel...

However as stated other then a horrible noise and a little bit of damage to the gears on the starter I cannot see how it would destroy your starter any more then when people do it by mistake in a key turn car.

Media centre PC - Case Silverstone LC16M with 2 X 80mm AcoustiFan DustPROOF, MOBO Gigabyte MA785GT-UD3H, CPU AMD X2 240 under volted, RAM 4 Gig DDR3 1033, HDD 120Gig System/512Gig data, Tuners 2 X Hauppauge HVR-3000, 1 X HVR-2200, Video Palit GT 220, Sound Realtek 886A HD (onboard), Optical LiteOn DH-401S Blue-ray using TotalMedia Theatre Power Corsair VX Series, 450W ATX PSU OS Windows 7 x64

ArtooDetoo

1044 posts

Uber Geek

Trusted

#440994 18-Feb-2011 07:57

riahon:

You could go super rad and have some sort of shield that slides back over the button like a jetfighter where you flick aside a plate, press the button and then is slides back over. That would be cool.

If you also placed the starter button on the right hand side of the steering wheel then the only one that can accidentally press it would be the driver.

The idea of an 'arm/disarm' cover is indeed a good one for preventing accidental activation, but it isn't a fail-safe in the event that some passenger might decide to try it out, which is what the OP was after, I think. And there's a 'cool' factor in having the starter button resemble those found in exotic cars, something I think the OP was also after, and having gone to the trouble of installing it, I doubt he'd want to then hide his work. Rather, I think he'd want it prominently displayed.

But there's much speculation on my part in the foregoing so I could easily be wrong. Pimping one's ride is very much a personal mission, and however it might seem to others, these mods are intensely important to the owner/builder.

Cheers,
R2D2

Galaxy S has gone to its new owner. HTC Sensation has gone to its new
owner. Galaxy S3 has gone to its new owner. Now using Galaxy Note 3. Skipping Note 4 I think...

Jaxson

8042 posts

Uber Geek

Trusted

#441000 18-Feb-2011 08:34

You'd want to put the switch in parallel with the key switch, ie don't disable the key start, so you can remove it at a later date if necessary. Or you can revert to the key if your other setup fails.

You'll need a proper immobilizer alarm as this technically makes your car very easy to steal.

Jaycar do 'missile' cover switches. I used one once to cover a boost solenoid button in a turbo car I had.
I see the do carbon fibre colours now too. They won't be wide enough to cover the 20mm type light I'm expecting you're intending to install though.

Placing the start button on the drivers side of the wheel is a simple work around, but I bet you want to locate yours right in the middle, where everyone can see it?!

As mentioned above, if creating a fully separate system, you will definitely need a fairly heavy gauge relay/contactor to achieve this as you can't run the full current required to turn the starter motor over through a tiny dash mounted switch.

Easiest way I can see is to setup the system to start the car by mimicking the existing ignition key switch. Get this working first. By this I mean a mains voltage rated dash switch that connects to the same wires as the steering column keys switch.

At this stage yes it will behave like the key which means if you press it you'll engage the starter motor again, even when the motor is going.

So the next stage is to interrupt your new circuit with a relay that opens when the engine is running. You have to find some signal for this. Off the top of my head I was thinking the signal the car stereo gets when the ignition is turned etc. I'll leave this over to you to discover a suitable low voltage trigger for this purpose.

Finally, you'll have to consider a few other things as well. Like the steering lock will be on if the key is not inserted and realistically you'll have to turn the key to the ignition position anyway to even 'arm' the car ready to be told to start.

Some car alarms have a remote start feature, but these don't go down so well if your car is not an automatic....

Good luck mate, hope some of the above was useful and not just really obvious anyway.
If it was me, I'd probably be talking to an auto sparky, they've probably dreamed this up in the past anyway....

cisconz

cisconz
1341 posts

Uber Geek

ID Verified

Trusted

Lifetime subscriber

#441006 18-Feb-2011 08:49

ArtooDetoo:

I'm no electrician, but I would think a simple solenoid would do what you're asking.

In the solenoid's 'relaxed' state, the contacts are bridged, completing a path to the live terminal of the starter motor's own solenoid. That path is then broken only by your starter button which, when pressed, completes the circuit to the starter motor and as long as the button is depressed, the starter will turn.

But... as soon as the engine fires, the charging circuit takes over the battery's task of supplying energy, so you can tap into that to feed power into your solenoid, energising it, which in turn pulls the bridge away from the contacts of your starter button circuit which then breaks that circuit and no matter how much you hold the starter button down, the circuit will remain broken by the solenoid.

The solenoid will only relax again and bridge the contacts of your starter circuit if the charging circuit is no longer producing sufficient voltage - that is, when the engine stops.

Maybe $60 for a solenoid, wire, fuse carriers (one for the starting circuit and one for the solenoid powering circuit), some spade terminals and solder.

In summary, your solenoid completes your starting circuit except for your start button. Push the button and power flows to the starter. As soon as the engine starts, the charging circuit (from the alternator and rectifier) fires up and the power from this circuit energises your solenoid, dragging the contact bridge away from the starting circuit, breaking that circuit and rendering the start button non-functioning.

As soon as the engine stops, however, the charging circuit voltage goes to 0 and allows the solenoid to return to its relaxed state, once again bridging the break in your starter circuit. Which means that when you push the start button, power will again flow to the starter. Bear in mind that the power for your start circuit should come from the ignition switch terminal that currently (no pun intended) is one position before the spring loaded key position.

I used to have push button start in my old car. I ran with 2 missile switches (acc and run) and one momentary (Start). This worked fine as noone touched the momentary while driving however the key start is designed a tad differently.

The key system has 4 switches

Acc - on when key in acc position and on position
On 1 - on when key in on position ONLY
On 2 - on when key in on position and start position
Start - on when key in start position ONLY

This is so that the battery is not drained by the stereo / aircon etc when the starter motor is trying to turn.

But now to the reason I quoted, as cars run a single dc system, for the solenoid to work you will need to put a diode between the alternator and the rest of the cuircut's as otherwie your solenoid will recieve voltage from the battery and the alternator so will never be in its "relaxed" state.

A diode at the correct current rating will not be cheap, someone else should be able to tell you where to get a diode that large.

Hmmmm

vinnieg

2260 posts

Uber Geek

Trusted

#441013 18-Feb-2011 08:57

Hmmm, what about finding a start button controller(again not too cheap) so the starter button stops working at voltages above 12.5(with alternator on it'll be roughly 13-15)

Are you still going to be running the start button with a key? Ie you turn the key to on, then press the start button?

What kind of car is it going into? I had a similar issue with my old Skyline, when I blew the starter inhibitor switch and had to wire up a temporary rocker switch until I replaced it.

I have moved across the ditch. Now residing in Melbourne as a VOIP/Video Technical Trainer/Engineer.

ArtooDetoo

1044 posts

Uber Geek

Trusted

#441021 18-Feb-2011 09:15

cisconz: But now to the reason I quoted, as cars run a single dc system, for the solenoid to work you will need to put a diode between the alternator and the rest of the cuircut's as otherwie your solenoid will recieve voltage from the battery and the alternator so will never be in its "relaxed" state.

A diode at the correct current rating will not be cheap, someone else should be able to tell you where to get a diode that large.

Thanks for your contribution cisconz. Makes sense. I wasn't envisaging taking the feed from the alternator>rectifier, but from the the charging circuit itself, which as you're aware, will already have a diode to provide a 'one-way' path, thus isolating the solenoid from battery power. But fitting a diode between the DC out and the solenoid should certainly work.

The solenoid could conceiveably be replaced by a relay which would reduce the current required. The trick with that though would be to find a relay that breaks rather than makes a circuit when energised, something that's not too common. But it's sure worth a look.

Either way, there's no impediment I can see to this working in theory. But as I pointed out earlier, I'm no electrician.

Cheers,
R2D2

Galaxy S has gone to its new owner. HTC Sensation has gone to its new
owner. Galaxy S3 has gone to its new owner. Now using Galaxy Note 3. Skipping Note 4 I think...

Jaxson

8042 posts

Uber Geek

Trusted

#441022 18-Feb-2011 09:20

ArtooDetoo: The trick with that though would be to find a relay that breaks rather than makes a circuit when energised, something that's not too common.

Just use the Normally Closed (NC) contacts on the relay output, or vice versa. There are only two options so one will achieve what you are after.

Lenovo

Shop now for Lenovo laptops and other devices (affiliate link).

vinnieg

2260 posts

Uber Geek

Trusted

#441025 18-Feb-2011 09:26

Forgot that my colleague was an ex auto electrician, he said:

Wire a relay into either the: oil pressure warning light(if you have it) or alternator feed, so when the alternator starts getting power or when the oil pressure light goes off(after starting) it trips a relay which cuts the feed to the switch

I'll see if I can get a more detailed explanation and a drawing off him

Edit: explained a bit more:

Earth(ground i guess he means) to the oil pressure warning light, so when the light goes off, the relay opens back up again.

I have moved across the ditch. Now residing in Melbourne as a VOIP/Video Technical Trainer/Engineer.

ArtooDetoo

1044 posts

Uber Geek

Trusted

#441026 18-Feb-2011 09:27

Jaxson:
ArtooDetoo: The trick with that though would be to find a relay that breaks rather than makes a circuit when energised, something that's not too common.

Just use the Normally Closed (NC) contacts on the relay output, or vice versa. There are only two options so one will achieve what you are after.

Good to know and thanks for that.

Cheers,
R2D2

Galaxy S has gone to its new owner. HTC Sensation has gone to its new
owner. Galaxy S3 has gone to its new owner. Now using Galaxy Note 3. Skipping Note 4 I think...

oxnsox

1923 posts

Uber Geek

#441029 18-Feb-2011 09:33

In essence the solution is as simple as r2d2 suggested.... you simply need a relay that energizes (when the engine starts) that disables the push button.

Most any qualified auto electrician should be able to install such a system for you... it's what they know how to do. If you're don't know what you're doing, or how to do it properly, then either get someone qualified to do it or don't do it a all.

Not being able to trust your passengers is not really relevant to the issue.

tombrownzz

147 posts

Master Geek
Inactive user

#441298 18-Feb-2011 19:29

with a starter button, is it secure? what happens if someone breaks into your vehicle and just pushes the button to start it without using a key?

vfxguynz

34 posts

Geek

#441309 18-Feb-2011 20:26

tombrownzz: with a starter button, is it secure? what happens if someone breaks into your vehicle and just pushes the button to start it without using a key?

Yea, the button is only functional when the key is on the AC/ON position, IE, the last click before you turn the key to activate the starter motor. All we're doing is adding a button to that last stage, completely useless, but rate fun nontheless! :P

vinnieg

2260 posts

Uber Geek

Trusted

#441831 21-Feb-2011 09:55

tombrownzz: with a starter button, is it secure? what happens if someone breaks into your vehicle and just pushes the button to start it without using a key?

It'll be the same as using a key, so hopefully Op has a immobiliser on his car...but it'll be as secure as needing a key. Anything can and will be stolen though

- Edited, half my sentence got cut off first time

I have moved across the ditch. Now residing in Melbourne as a VOIP/Video Technical Trainer/Engineer.

kyhwana2

2566 posts

Uber Geek

#441837 21-Feb-2011 10:17

Aaroona: My new car is currently getting certified etc and I am wanting to install a starter button.

I just have a few questions though;

How am I able to stop the button from burning out the starter motor if the button is pressed while the car is running? A mate of mine has just wired up a start button in his car, but his will burn out the starter motor if its pressed while his car is running - a potential problem if you have people in your car who are sticky fingers and like to fiddle.

Try something like this?
http://www.japanprobe.com/2006/07/19/usb-nuclear-launch-button-get-yours-at-rakuten/
;)

Or at least get the flippy plastic bit or key to unlock flipping bit, etc. It might take away the convience of a start button, but it'll look cool!

langers1972

1039 posts

Uber Geek

#442257 22-Feb-2011 09:56

oxnsox:

Most any qualified auto electrician should be able to install such a system for you... it's what they know how to do. If you're don't know what you're doing, or how to do it properly, then either get someone qualified to do it or don't do it a all.

Yep see this

1 | 2 | 3 | 4