Safety Switch

[Donmon]

An earlier thread got me thinking about my own ride, I am at the wiring stage and was going to say " hell i dont need any stink-in safety switch". Then the dad in me came out and I felt I better run one. I was thinking about using the stop light switch ti interrupt the wire from the starter button to the solenoid, any electrical guru's wanna chime in on this and tell me if this will work? Thanks, Don

 

[ellis8500]

What aspect of safety are you trying to address? Brakes on to start? Oil pressure needed to run? Either of these should be independent circuits. If you have to rely on your brake switch for a signal, have it energize a relay so that your safety circuit is not directly tied to the brake switch.

 

[fordsbyjay]

I just used the neutral safety switch on my shifter. I don't know if I am getting older now or what but I feel it is something every car should have. Twenty years ago I wouldn't have thought twice about not having one.

 

[Donmon]

What aspect of safety are you trying to address? Brakes on to start? Oil pressure needed to run? Either of these should be independent circuits. If you have to rely on your brake switch for a signal, have it energize a relay so that your safety circuit is not directly tied to the brake switch.

I guess I should have outlined my intentions better, I would like to have a system in place so that the brakes have to be applied before I can turn over or start the car. I would rather not put a neutral safety switch in because of the location of my shifter. I was hoping this simple bit of wiring would do the trick, I just wanted to run it by you guys to see if I was over looking something in my thought process. Thanks, Don

 

[fordsbyjay]

I guess I should have outlined my intentions better, I would like to have a system in place so that the brakes have to be applied before I can turn over or start the car. I would rather not put a neutral safety switch in because of the location of my shifter. I was hoping this simple bit of wiring would do the trick, I just wanted to run it by you guys to see if I was over looking something in my thought process. Thanks, Don

The downside to this is you need to get in your car to start it which is something I never do. Usually I just reach in and start it so it can run a few minutes and warm up before driving.

 

[Donmon]

The downside to this is you need to get in your car to start it which is something I never do. Usually I just reach in and start it so it can run a few minutes and warm up before driving.

True, I guess my wanting to do this comes from my dragster days when its an NHRA rule you have to have someone in the cockpit. I dont mind getting in to start it. Guess Ill wire her up this way and see what happens.

 

[rooster57]

I think that is a great idea. but i am on board with the brake switch feeding a N/O relay and the loop your start circuit through the contacts

 

[Donmon]

I think that is a great idea. but i am on board with the brake switch feeding a N/O relay and the loop your start circuit through the contacts

So is this what your referring to? (im a picture guy)

-Don

 

[ellis8500]

Move the Start Button to be between the brake light switch and the relay. As shown, you will energize the relay whenever you apply the brakes. Use the relay contacts to as the actual starting switch. This way, no high current through any of the switches.

 

[rooster57]

My thought was to Let the 12 volts from the brake switch energize the relay in turn when the relay closes then the start button has power (through the contacts) to start the car . When the brakes are not applied the relay is open and their is no power to the start button.

 

[Donmon]

I understand what your saying Mr. Bill, but rooster nailed it the starter button would be dead unless the brakes are applied, thats what I was shooting for, do you see a problem with energizing the relay every time the brakes are applied? Will that lead to pre mature failure of the relay?
Great input -Thanks, Don

 

[ellis8500]

If you move the start button as I suggested, when you apply the brakes you have power to the button. Pressing the button energizes the relay which then sends power to the starter [solenoid if you are using one]. I doubt the relay will wear out faster, but you might get irritated if you hear the "click" every time you apply the brakes.

 

[Donmon]

If you move the start button as I suggested, when you apply the brakes you have power to the button. Pressing the button energizes the relay which then sends power to the starter [solenoid if you are using one]. I doubt the relay will wear out faster, but you might get irritated if you hear the "click" every time you apply the brakes.

Ohh I think I get what you where saying, take a look at this diagram, is that what you mean?

-Don

 

[rooster57]

If you can hear the relay click over those side pipes you have supersonic hearing. Most relays are good for more starts than the starter is good for .

 

[ellis8500]

Yes, that's what I meant. Either way will work. My suggestion results in lower current through the button.

 

[Donmon]

Yes, that's what I meant. Either way will work. My suggestion results in lower current through the button.

I concur Mr Bill, thanks for the input. I hope to be wiring her up in the next couple weeks.

-Don

 

[guilld]

Amen to some kind of safety switch. Unknown to me the one on our car was not working. I started in in gear and came within a frog's hair of running all over the back of my wife's BMW Z4. I heard of local guy who started a 41 Williys without a switch and ran it through a garage. After my experience I will never have a rod without some type of safety switch.