push button start and relays

  Cool.  I have been kicking it around this week and the IC is the only way I can figure it out.  If all else fails, I will do it with an on-on-momentary toggle switch for now.  I guess I can eventually figure it out with some studing.  Any ideas to do it another way or the describe about IC with relays would be great.  Thanks.

here is a quick idea,it will keep the relay on untill the input gets to 8 V, that is adjustable from 3.2 -> 9.6 V with the 10K pot, you would want to use a high power opamp if driving the relay right off of it unless the relay has a high coil resistance might wanna put a transistor in. Also this really will not do much you still have to add all the other circuitry, but thats my idea based around a difference amplifier. Hope this is of some use to ya.

  xetmes - that is the idea I am looking for.  Now you have the variable input as a DC current.  The tach is going to be AC; is this going to matter?  Also, by the pot, you look to have put a cap.  Is that right or is the picture missing something?  What value is it, ect.

  soundinstaller - I just prefer to keep the cost down with a $5 IC instead of a $25 remote start.  Either way, outline it for me if you could and suggest a rm maybe.  I figure you don't connect the switch for the brake kill, don't set the timer and hard wire the rf reciever to the push button to simulate a remote input.  Question is, will you piss off the rs gem with a constant input from the bridged push button switch?  Remember, there will be a constant input, not just a small fixed one like a remote pulse.  Maybe/Hopefully I missed something.  Like I said, outline it for me if you could so I can figure it out.  Thanks.

ok i did i little more thinking, note this may not work at all, it would in theory and does in simulation, but that does not mean it will in real life, but just my ideas...

This will keep the relay closed from an input of 0V -> 8V, at 8V the relay will open and the connection lost.