auto on switch

[acrbill]

I have a traction control in my car and by default its on, and there is a button to switch it off. It resets itself everytime I start the car. Is there a simple way to build a circuit that will set the traction control to off every time I start the car??


Please excuse my ignorance of electronics .

 

[gerty]

What type of switch is in your car now? normally open/ closed momentary pushbutton? If it's normally closed you could try unplugging it to simulate pressing the button..your vehicles computer may detect this ploy and throw up some sort of error signal..We need to know if it's open or closed contacts to determine if the "circuit" will go in series or paralell...

 

[acrbill]

when I unplug the switch it stays at the default on position.

let me know what I need to look at/test to give you the info you need.

thanks for the quick reply

 

[gerty]

Sounds like it's a normally open circuit..Assuming it's only a 2 wire switch (one set of n/o contacts) all we need to do is close the circuit.Try jumpering out the switch socket (after unplugging)wire a small jumper and start the motor..Basically all this does is change the control from momentary to maintained..If that doesn't work try wiring a small 12v relay (coil) from the starter wire (only hot when key turned) to ground.
Then wire a set of n/o contacts to the original switch connector.This will mimic you pressing button..There's probably 100 ways to do this but I'm trying to keep it simple(cheap)

 

[acrbill]

ok I just went out to look at the connector for the switch. There are 3 wires :? Ill call them 1-2-3

if I jump 3-2 or 3-1 the trac control (tc) turns on or off. so if I jump 3-2 the TC turns on if I take the jumper out it stays off, but if I replace the jumper in the same spot it turns on again. I can do any combo of 3-1 or 3-2 and it will turn off and on each time. Hopefully this makes more sense to you than it does to me.

feel free to him me up on AIM-bill323 if you have any ideas.

 

[gerty]

What you'll have to do is meter (ohmmeter ) your button to see what contact configuration you have.. With 3 wires you could have a common/normally open/normally closed..Impossible for me to determine from here..Once you identify the button contacts , mimic them with the relay contacts comm/no/nc..You'll probably have to add a capacitor (1,000uf) accross the coil connections (watch polarity!) to keep the relay energized for a few seconds in case the car computer doesn't look at the input right away..In above post I mentioned wiring relay to starter wire that's hot when key turned- I mean in start position- not the run position.
Hope all this helps...

 

[acrbill]

ok, I took the switch apart and snapped a few pics of the board.

**broken link removed**
**broken link removed**

I have continuity between 2&3 when the switch is depressed.

any idea what my next step should be?

 

[jcaluma]

may i know what is the blue thing in the board?...

 

[acrbill]

may i know what is the blue thing in the board?...

Thats the light that lights up the switch when the trac control is off.


on a side note to anyone with ideas. I want the switch to default to the off position, but... I want the switch to function so I can turn it on if I wish.

you guys are the best! 8)

 

[Brocktune]

What kind of car do you have?

You might want to do a web search and see if there are any aftermarket electronic devices that reverse the operation of the switch like you desire. There is one for my car...for about $60 I think...there might be one for your car too. A lot of people don't like the default to "ON" so some companies build modules to reverse it.

 

[acrbill]

What kind of car do you have?

You might want to do a web search and see if there are any aftermarket electronic devices that reverse the operation of the switch like you desire. There is one for my car...for about $60 I think...there might be one for your car too. A lot of people don't like the default to "ON" so some companies build modules to reverse it.

im glad you mentioned that. I was fairly confident there was no ready made device for my car so I never even looked. I just googled it and came across a site where a guy made a simple circuit that made the TC default to off.

**broken link removed**
He mentions- "The computer sees the switch as closed when the resistance between those pins is less than 9K ohms, and open otherwise. "

Im gonna hook up a pot to the wiring harness and see where the switch gets triggered at.

Can I pick any resistance under the amount of ohms that triggers it? Also the article mentions a -470 uF CAP and Gerty mentioned 1,000uf .

Is there a way to tell what the best CAP to get is? Or will I be ok with either one of those.

Thanks

 

[Brocktune]

im glad you mentioned that. I was fairly confident there was no ready made device for my car so I never even looked. I just googled it and came across a site where a guy made a simple circuit that made the TC default to off.

**broken link removed**

I'm not sure what the resistor is for though. He mentions- "The computer sees the switch as closed when the resistance between those pins is less than 9K ohms, and open otherwise. "

There is probably a good reason for the resistor, but I know nothing of electronics.

I would only try the circuit mentioned in the link if you have an M3/M4 of the same year.

Another suggestion: do another search for "<your car model>, message board" You can register at a message board related to your specific car and ask some of those guys.

I drive a mustang and I get tons of info about modifying my car from a mustang message board.

 

[olly_k]

I'm not sure what the resistor is for though

The resistor and capacitor make an R-C time constant - without R, c would charge almost instantaniously. therefore the resistance would be above 9k by the time the micro tests the status of the switch. Assuming this works (which may depend on source impeadence etc) it is quite an elegent solution.

 

[acrbill]

The car in question is a Neon. I am a long time member of every Neon board out there.

I am a pioneer of the Neon community when it comes to this subject. 8)


On a side note: I used to have a 99 Mustang GT. The Trac control made me look like quite the fool one time. I thought I would show off in front of my buddies by flipping a 180. Halfway through the manuever the mustangs elaborate (pulls timing and uses abs on the rear wheels) TC system kicked in and the car bogged down stopped me in my tracks . From all accounts it looked cool from the outside. 8)

 

[acrbill]

I'm not sure what the resistor is for though

The resistor and capacitor make an R-C time constant - without R, c would charge almost instantaniously. therefore the resistance would be above 9k by the time the micro tests the status of the switch. Assuming this works (which may depend on source impeadence etc) it is quite an elegent solution.

Duly noted, friend.

I actually came to that conclusion myself while in the shower ( all my great ideas are produced there :lol: )

Im going to give it a shot.

wish me luck

 

[Sebi]

I mean, when You start the car, the voltage drop resetting the circuit. Try connect a serial diode and a paralel 2200uF capacitor with power input of electronic unit.

 

[Brocktune]

The car in question is a Neon. I am a long time member of every Neon board out there.

I am a pioneer of the Neon community when it comes to this subject. 8)

Please tell me it's an SRT-4! 8)

 

[acrbill]

I mean, when You start the car, the voltage drop resetting the circuit. Try connect a serial diode and a paralel 2200uF capacitor with power input of electronic unit.

That went right over my head. :? I think I understand the first part. When I click key to the run postition the circuit does its thing. Then the car starts and the voltage drop resets the circuit. The guy mentioned that if you restart the car the circuit wont reset the way I want it to.

Please tell me it's an SRT-4! icon_cool.gif

No sir. Its a Neon ACR.

 

[acrbill]

I have another idea now. Since a capacitor won't work since the circuit will reset after I crank the car over, I figure I need some sort of delayed reaction. After scouring the net I found the 555 timer. Since i'm still a über n00b when it comes to electronics I couldnt figure out how to make the timer work for me. If anyone can help me figure out how to make the 555 timer work for me I would appreciate it. Here is a pic to make it easier for you to explain it to me.




**broken link removed**

 

[gerty]

**broken link removed**
Here ya go ..You want 'generating a delayed pulse' on the left side of the schematic where it shows the switch , just connect directly to ground and the positive to your fuse panel so it's 'hot' when key is on..Connect the relays normally open contacts to the switch wires for pins 2&3.. I would leave the original button operationable , so you have to strip the wires to it and solder to them for the relay contacts. You probably need to change the timer on the left to give a little more time ,probably change the 22uf to 33uf ought to do it..keep us posted...