Msd 2 Step Help
- Thread starter smkshw
- Start date
well i thought there was 12v power to the clutch switch but apparantly it just grounds.....i wanted to have it activate when clutch is pressed...did some reading and i guess some kind of relay is needed to make it work that im not sure how to do yet?
for now i have it hooked up to my horn button and it works great actualy,but i realy would rather have it wired to the clutch!....if anyone can give me some help with this i would be very thankful!....not sure what relay people were talking about?
I attached an image of how mine is run. You are correct, there are only ground switches on the clutch. Its been a while, but if you look at the clutch switches, there are two sets of wires, each set has three wires if I remember correctly. I think one set may be for the cruise control, but I am not certain. Again, it has been a few years since I have done this, but I believe you want to search the set of three red wires. It may be the top wire of those three, but I stress that I cannot remember exactly.
The ground is only complete when you press the pedal to the floor. With this setup, you will press the clutch to the floor, toggle the momentary switch to latch the relay, and as soon as you release the clutch, the relay will unlatch and the 2 step will turn off. Using the momentary switch to complete the circuit prevents the two step from being reactivated every time you press the clutch in.
I modified this diagram just a touch to include my linelock. It feeds off the same ground path as the two step, this way I can use the linelock to hold my car in place when I stage and prevent rolling forward or backwards (a real problem at one of the tracks I go to).
Joe
The ground is only complete when you press the pedal to the floor. With this setup, you will press the clutch to the floor, toggle the momentary switch to latch the relay, and as soon as you release the clutch, the relay will unlatch and the 2 step will turn off. Using the momentary switch to complete the circuit prevents the two step from being reactivated every time you press the clutch in.
I modified this diagram just a touch to include my linelock. It feeds off the same ground path as the two step, this way I can use the linelock to hold my car in place when I stage and prevent rolling forward or backwards (a real problem at one of the tracks I go to).
Joe
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first off thanks....thats the diagram ive been seeing,what i dont undresand and what scares me is my msd box says it needs a 12v source to activate,in that diagram it shows it being grounded?....and shows two seperate rev and 2step units?...does the relay change it to ground then or somthing like that?,i have it to my horn button and it gets the 12v and activates....?
Look at the relay diagram. The two step will have its black wire permanently grounded at all times. The red 12v wire on the two step will get its 12v from pin# 87 on the relay. Pin# 87 is getting its power from pin# 30. However, when the relay is open (not activated) the connection between pin# 87 and pin# 30 is broken.
In order to close the gap between pin# 87 and pin# 30, a 12v current has to travel between pins# 85 & 86. If you wire pin# 86 to your grounded clutch switch, then pressing the clutch to the floor will ground pin# 86. You would then press the momentary switch, which is connected to a permanent 12v source. This allows current to flow from pin# 85 to pin# 86, which in effect, closes the connection between pins# 87 & 30, which allows 12v to run through the red 12v wire of the 2 step.
Once power is established between pins# 87 & 30, the jumper wire runs power back to pin# 85, which keeps the relay activated, without you having to hold the momentary switch on. Once you release the clutch pedal, the ground to pin# 86 is broken, which opens the relay, causing 12v to be lost to the 2 step, thus turning it off.
When I first started messing with relays, it confused the living daylights out of me. They are a pretty neat little device though. I hope this helps clarify things a little. If not, the diagram does work. I attached my modified version for the line lock as well. I added a separate switch so I could use the line lock by itself, and also installed a diode to prevent 12v from feeding back and keeping it activated.
Good luck!
Joe
In order to close the gap between pin# 87 and pin# 30, a 12v current has to travel between pins# 85 & 86. If you wire pin# 86 to your grounded clutch switch, then pressing the clutch to the floor will ground pin# 86. You would then press the momentary switch, which is connected to a permanent 12v source. This allows current to flow from pin# 85 to pin# 86, which in effect, closes the connection between pins# 87 & 30, which allows 12v to run through the red 12v wire of the 2 step.
Once power is established between pins# 87 & 30, the jumper wire runs power back to pin# 85, which keeps the relay activated, without you having to hold the momentary switch on. Once you release the clutch pedal, the ground to pin# 86 is broken, which opens the relay, causing 12v to be lost to the 2 step, thus turning it off.
When I first started messing with relays, it confused the living daylights out of me. They are a pretty neat little device though. I hope this helps clarify things a little. If not, the diagram does work. I attached my modified version for the line lock as well. I added a separate switch so I could use the line lock by itself, and also installed a diode to prevent 12v from feeding back and keeping it activated.
Good luck!
Joe
