Push-To-Start Button

arcsine · 08-31-2006, 11:21 AM

By sheer dumb luck, the lock on my car necessitates a key to be shaped such that the deepest cuts are vey near to the base of the key. This makes the key weakest there. I am concerned with the torque resistance I feel when starting the car that I will shear off the key at this point which leads to a a situation I would prefer to not to have to deal with.

Rather than replacing the still functional ingnition switch and re-keying the door locks, I though of another solution. Place a momentary contact swtch to act as a starter button to relieve the ignition switch of that responsibility. I still would use the key for switching on power and security but no longer have the worry of rendering the car dead by having a broken key in the lock.

Is there something I am missing in this solution? Ideas and opinions are welcome.

Eric-325I · 08-31-2006, 11:40 AM

Would be cool if you did a thorough write-up with pics of what you end up doing.

Eric

911pcars · 08-31-2006, 12:19 PM

Eric,
Sorry I took so long with your request.

Gary,
Go here.

Mine is an early 911, but the ignition wire is the same color to the starter solenoid.

Hope this helps,
Sherwood

kucharskimb · 08-31-2006, 12:26 PM

just make sure you can unlock your steering wheel...

BK911 · BK911's Garage

I did this a couple of weeks ago in a 914 bacause the switch was worn. I ended up splicing a switch between the yellow and black wire in the ignition switch (terminal 30 and 50 in the schematic). So you still need the key to turn to the on position but the switch acts as the start position. All I needed was a rated switch, about 6 inches of wire and two splice thingies.

arcsine · 08-31-2006, 01:00 PM

Cool. No one pointed out something silly I had overlooked.

Sherwood and BK911. Thanks for the info. This is perfect for what I was thinking. When I do it, I'll take pics and post it.

Matt, I will be keeping the standard ignition and lock which will function as before. I am just moving the starting function to a separate switch.

Noah930 · Noah930's Garage

That idea is so rice!

* Image taken from S2000 site.

j/k Sounds like a decent idea. Extra points if you can make the installation look OEM, too.

scottb · 08-31-2006, 01:11 PM

Would it be the worst thing in the world to have an ignition key that's different from the other locks? IMHO, it's no big deal to carry two different keys, and instead of messing around with a starter button I'd simply re-key the ignition switch, or replace it.

My $.02.

Emission · Emission's Garage

So, you put the START button on the left or right of the steering wheel?

:-)

BK911 · BK911's Garage

I didn't want to use a start button, but I couldn't find a replacement switch for my car. So less than 1/2 hour later I was on the road again. I hid the switch under the dash so it isn't visible. Is that still rice? :-)

scottb · 08-31-2006, 01:23 PM

If you're really going to do this, you might take a look at this switch. It's an aircraft starter switch, and has a black rubber boot.

http://aircraftspruce.com/catalog/elpages/pusbutswitch.php

911pcars · 08-31-2006, 01:28 PM

Quote:

Originally posted by BK911
I did this a couple of weeks ago in a 914 bacause the switch was worn. I ended up splicing a switch between the yellow and black wire in the ignition switch (terminal 30 and 50 in the schematic). So you still need the key to turn to the on position but the switch acts as the start position. All I needed was a rated switch, about 6 inches of wire and two splice thingies.

That works too. However, using a separate relay to energize the solenoid bypasses any issues with voltage drop in the switch and the 10' yellow wire.

"Would it be the worst thing in the world to have an ignition key that's different from the other locks? IMHO, it's no big deal to carry two different keys, and instead of messing around with a starter button I'd simply re-key the ignition switch, or replace it."

No, not at all. I have later door locks so I also carrry two different shaped keys for doors and ignition. BTW, some early ignition switches are NLA, thus the requirement to lengthen the life of the existing switch.

According to Pelican's catalog, these are the choices:
prior to '70 (not listed in catalog)
70-89: Complete ign. switch, $512.00
Electrical portion, $57.00

The urgency for a separate switch might be proportional to its availability and cost. BTW, I see no blingness in a remote button unless it's larger than 2" (game show size), or has flashing/sequential lights advertising its location or purpose.

Sherwood

arcsine · 08-31-2006, 01:50 PM

scottb, that is exactly what I would want. You just saved me an hour of searching. Thanks

MAS956 · 08-31-2006, 02:18 PM

+1 for Sherwood's schematics. I followed them almost exactly and the switch works perfectly every time. FWIW, I used a MOM rocker switch I got here that fit perfectly in the dash blank next to the DS air vent.

Good luck!

Drago · Drago's Garage

Quote:

Originally posted by arcsine
scottb, that is exactly what I would want. You just saved me an hour of searching. Thanks

No, no, no...that's not what you want Gary.

You already have the perfect momentary switch staring you in the face when your sitting behind the wheel.

911pcars · 08-31-2006, 02:48 PM

Mark,
Thanks for validating the electrical diagram works.

Sherwood

arcsine · 08-31-2006, 07:41 PM

Sherwood,
In your diagram, you have the power lead to the new starter switch fused with an existing 5A fuse. As this would be key-on powered, which one are you using or tapping into? I have an idea but would like to hear from an expert.
Thanks again for the help.

911pcars · 08-31-2006, 09:40 PM

"In your diagram, you have the power lead to the new starter switch fused with an existing 5A fuse. As this would be key-on powered, which one are you using or tapping into? I have an idea but would like to hear from an expert.
Thanks again for the help."

Expert? (ha)
The main power circuit is from the battery terminal on the solenoid to the Bosch relay, then to the solenoid. The low current path to energize the control circuit of the Bosch relay is from the 5A fuse and the remote switch.

The source voltage to the remote switch and relay is not at the ignition switch but from the main fuse box. Thus, the remote switch can crank the engine indepedently with the ign. switch ON or OFF.

Hope this helps,
Sherwood

Porsche · Porsche's Garage

I suggest having an LCD screen running Windows XP where you use a mouse to click on the START button... actually, that's not as funny when you actually type it out and read it...

k9handler · 09-01-2006, 12:18 AM

I was thinking of this combined with a kill switch on the top of the dash. Wonder if it could be as simple as insert kill switch key, and push button to start. How would that work?