wes65

iTrader: (7)

So, my launch control used to work. I had a switch between pins 12 and 13 so that i could turn it on and off. One day, it just stopped working. I removed my switch and just directly connected pins 12 and 13 on the center connector. Still no dice. So then, i email diy and they say to test the switch on the clutch pedal, the one farthest from the firewall. I pull the switch out and it has continuity when the clutch pedal is depressed and it does not have continuity when the pedal is not depressed. I assume this is how it is supposed to be. I would like to use the stock switch, however, if it came down to it, i suppose i could use a momentary pushbutton switch mounted on the steering wheel or something. Hmmm, im thinking maybe the left horn button?

Any ideas on what could be causing this?

Thanks in advance,
Wes

wes65

iTrader: (7)

Oh, sorry i should post up my msq.

Matt Cramer

Could you check the voltage on that wire loop on the center connector? It should be at battery voltage and drop to 0 when you put the pedal in.

wes65

iTrader: (7)

Yeah, i will be able to check that tonight. Thanks!

wes65

iTrader: (7)

The voltage on the loop between pins 12 and 13 is 13.7 volts all the time, clutch in or out. Think its a problem with my MS?

Matt Cramer

Sorry, I should have said battery voltage rather than 5 volts and will fix my previous post. The Megasquirt is working, the clutch switch isn't.

wes65

iTrader: (7)

hmm, maybe it's the wiring, i checked the switch and it is good. I should be able to hook up a momentary switch between pin 12 and the ground and use that, correct?

Matt Cramer

Yes.

wes65

iTrader: (7)

I've done that and still no dice. I hooked up a spst momentary pushbutton between pin 12 and a chassis ground and it did not work. I also just grounded pin 12 to see if i could get it to come on and still nothing.

Matt Cramer

Does that drop the voltage to zero?

wes65

iTrader: (7)

If i hook the multimeter up with one lead on each side of the switch, it should show battery voltage until i press the button, then it should show 0. Is that correct? I will have to go check on it.

Matt Cramer

Yes, that's correct.

wes65

iTrader: (7)

Well, i finally got a chance to mess with it again. The voltage does drop to zero, so i know that my momentary is good. Any other suggestions?

Matt Cramer

If you don't mind doing some tests with the cover off the MSPNP, check the voltage on pin 3 of the breakout header. Does the voltage go from 0 to 5 volts and back when you ground and unground the launch control input? Let me know what it's doing there.

wes65

iTrader: (7)

I will see what i can come up with, is it pretty straight forward to take the cover off?

Matt Cramer

Just 4 screws.