Engine crank with button

Not sure what you mean by **AT** the starter - there is no reason i should have to go under the hood to do any of this. I am tapping into the wires where the key goes into the cylinder. If the car can auto start successfully (and it does) off those wires then I should be able to tap into the exact same set of wires and start the car with just a button. especially when the key is already in the RUN position. John

You say there is an autostart in the car.  Drop the unit, open it up and activate the starter relay with the key on.  If it cranks, you can wire your push button to this (-ve).  Dose the autostart have antigrind rely wired in?  Try connecting at or down stream of the units tie in.

the starter relay inside the brain is connected to the cars yellow starter wire. so if we connect to it inside the brain or outside, then it should be the same thing. in other words, it should be the same thing if the alarm is giving the starter wire 12v or the button is giving it 12v. the alarm does have an anti-grind feature and so does the car itself (GM put that feature in corvettes). We tied the button to the starter wire directly where it goes into the dash and out to the starter system so that none of the alarm business should affect it. With the key in RUN, the ACC and other wires are receiving the voltage they need. The VATS is seeing the proper resistance from the key pellet and the clutch switch see's 12 volts when the clutch is pushed in. What else needs to happen besides these few things?

calee4nyaboy wrote: Not sure what you mean by **AT** the starter - there is no reason i should have to go under the hood to do any of this. I am tapping into the wires where the key goes into the cylinder. If the car can auto start successfully (and it does) off those wires then I should be able to tap into the exact same set of wires and start the car with just a button. especially when the key is already in the RUN position. John

 There is no reason why the pushbutton shouldn't work either.. but it doesn't.  The key cranks the car.. the autostart cranks the car.. your pushbutton doesn't crank the car.. Sounds like a problem with the pushbutton circuit. So go back to the basics and check everything.. check for 12v up to the pushbutton. Check for 12v out of the pushbutton when the pushbutton is pressed. Check for 12v at the other end of the yellow wire, at the starter, when the pushbutton is pressed.

 No, you shouldn't have to go under the hood.. but this should have been something simple. How much time have you spent on this that you could have spent doing something profitable?

I have checked ALL the wires including before and after the button. the button receives 12v and it gives 12v to the yellow starter wire when pressed (just like the auto-start does) In fact, I ran my own wire straight from the battery to the yellow starter wire (with the key turned to RUN, and it STILL didnt start) This has got to be a matter of the car not seeing the VATS resistor pellet or the clutch is not pushed in for it to not start. WE HAVE CHECKED THESE TWO THINGS SO THEY ARE NOT AN ISSUE, this is just an example. Thats why i keep saying what other little things like this need to happen for it to start. As far as time, I have all the time I need, it is not an issue what-so-ever...I just want it done right and working since it shouldnt be difficult. John

calee4nyaboy wrote: I have checked ALL the wires including before and after the button. the button receives 12v and it gives 12v to the yellow starter wire when pressed (just like the auto-start does) In fact, I ran my own wire straight from the battery to the yellow starter wire (with the key turned to RUN, and it STILL didnt start)

 Have you determined exactly where that yellow starter wire goes to?

calee4nyaboy wrote: This has got to be a matter of the car not seeing the VATS resistor pellet or the clutch is not pushed in for it to not start. WE HAVE CHECKED THESE TWO THINGS SO THEY ARE NOT AN ISSUE, this is just an example. Thats why i keep saying what other little things like this need to happen for it to start.

 How have you determined that the clutch switch and VATS system are working properly?

calee4nyaboy wrote: As far as time, I have all the time I need, it is not an issue what-so-ever...I just want it done right and working since it shouldnt be difficult. John

'...since it shouldn't be difficult.'

 Here's a hint.. that yellow wire doesn't go anywhere near the starter..

 The yellow wire goes from the ignition switch (start position) to the instrument panel fuse block - fuse 14 (10a).

 The 'center' of the starter circuit is the Theft Deterrent Relay.. looks like a standard four terminal relay. Using standard relay numbering, terminal 30 is connected to a 60 amp fuse in the fuse block (looks to be fuse 52) That fuse is connected to B+. Terminal 87 is connected to the starter solenoid. This covers the power side of the relay.

 The coil side of the relay.. terminal 85 comes from the clutch pedal start switch.. the other side of the clutch pedal start switch is connected to our old friend yellow wire from the ignition switch (after it passes through fuse 14 and turns to the color purple). Terminal 86 comes out of the Theft Deterrent Relay and goes to the BCM. (Hey look... computer controlled starter!!)

 Depressing the clutch sends power to the coil of the Theft Deterrent Relay.. the BCM gives the coil a ground path and throws the relay, which engages the starter.

 Looks like probing the four wires on the Theft Deterrent Relay should tell you why the starter isn't starting..  might not tell you exactly why, but at least gives you a place to look.

NOTE - the terminal designators are for informational purposes only..

 Again.. all this information would be on a decent schematic along with wire colors.. see if you can get one.

 The reply that someone posted about the yellow/blk wire looks to be correct.. the yellow/black wire is the wire from the Theft Deterrent Relay to the BCM.

 Jim

Jim, AWESOME information. Thank you! The only wire that I have not looked at is terminal 86 of the theft deterrent relay that you mentioned comes from the BCM which energizes the relay during start. I have tested both sides of the clutch wire (yellow and purple) and they are working as normal. also tested the vats and its working as normal. the button is working as normal giving 12v when pressed. with all the information we have in front of us, i still have to say i'm confused as to how the auto starter can start the car without having to go to the theft deterrent relay. i guess i've been scratching my head thinking "what is the auto-starter doing that i'm not doing??" i figured turning the key to RUN will give all the wires coming out of the ignition harness the juice they need except the yellow starter. it will also allow the VATS to pass its resistance test. so, i gave 12 volts to the clutch and to the starter wire just to be sure both were covered but it still wont start. Is there something off the top of your head that you can think of that an auto starter has to do that im not doing? John

calee4nyaboy wrote: Jim, AWESOME information. Thank you! The only wire that I have not looked at is terminal 86 of the theft deterrent relay that you mentioned comes from the BCM which energizes the relay during start.

 No no no... the wire that comes from the BCM to the theft deterrent relay is the GROUND path for the relay coil.. power for the coil comes from the clutch switch.

calee4nyaboy wrote: I have tested both sides of the clutch wire (yellow and purple) and they are working as normal. also tested the vats and its working as normal. the button is working as normal giving 12v when pressed. with all the information we have in front of us, i still have to say i'm confused as to how the auto starter can start the car without having to go to the theft deterrent relay. i guess i've been scratching my head thinking "what is the auto-starter doing that i'm not doing??"

 I don't know how you're testing the VATS system.. I'd be using a scan tool that interfaces with the vehicle computer.. what are you doing?

 There are people here that are more knowledgeble than I about remote start systems; having said that I'd suspect that the auto start system has to tap into the circuit after the clutch switch unless someone's bypassed the clutch switch (specifically, there has to be a workaround for the auto start and the clutch switch). I'm wondering if the auto start wire connected to the yellow starter wire at the ignition switch is a sense line, not an output line. 

calee4nyaboy wrote: i figured turning the key to RUN will give all the wires coming out of the ignition harness the juice they need except the yellow starter. it will also allow the VATS to pass its resistance test. so, i gave 12 volts to the clutch and to the starter wire just to be sure both were covered but it still wont start. Is there something off the top of your head that you can think of that an auto starter has to do that im not doing?

  By probing the wires at the theft deterrent relay you should be able to determine where your problem lies.. we can eliminate the power side of the relay because the vehicle does start normally.. which leaves us with the coil side of the relay. Two wires.. one yellow and one yellow/black. Yellow should go hot when you press the starter button (with the clutch pressed). The yellow/black wire should be grounded.. I suspect this is where your problem lies; the BCM is not enabling starter.

 I wasn't kidding when I said computer controlled starter..

 What djfearny said in his post still holds true.. the yellow/black wire has to go to ground for the theft deterrent relay to allow the starter to operate.

 regards,

 Jim

Jim, I knew what you meant about terminal 86 being a ground wire...my terminology might have thrown you. Since it takes a 12v connection AND a ground to energize a relay, I personally (in my own weird head) think about them as both being the wires that "energize" the relay...hope that makes sense. Anyway, this problem was bugging me last night (to the point where i couldnt even sleep...lol) Basically, I thought of every wire that the auto-starter does and to make sure that it's been replicated when the button is pressed. I know that the VATS system works properly because the car starts with the key and it starts correctly with the auto-starter (and its VATS by-pass relay) Well, since the car acts just like the VATS is not working when the button is pressed, I started to think even though the key is in and turned to RUN maybe its not running through the VATS for some reason. You would think it would because the key is in and the resistor pellet would then be read. Then I thought maybe the VATS only engages DURING the crank position. If that is the case then it makes perfect sense why it wouldnt start. All i'd have to do is trip the VATs by-pass relay (that works when the car auto-starts) and it would then see the proper resistance. I think another thing the VATS does when its tripped, is that it has something to do with sending the ground wire to pin 86 of the theft deterrent relay. I'll try this idea and let you know. Thanks, John

okay, I have absolutely had it! I checked all the wires over and over again. Again, the auto-start works fine so here is a run down of how the alarm is wired and what it does and then in CAPS WHAT I'VE DONE TO EMULATE IT: 1) The auto-start alarm gives 12v to the ACC and to the 2 ignitions. PUTTING THE KEY IN TO THE RUN POSITION DOES THAT (ALSO TESTED WITH A METER TO VERIFY). 2) Then the alarm trips the VATS relay and dummy resistor so the car thinks the key is in. I TRIPPED THIS MANUALLY BY ENERGIZING THE RELAY SO I KNOW THE VATS COMPUTER IS SEEING THE RESISTANCE IT NEEDS TO SEE. 3) Lastly, the auto start's START wire gives the yellow clutch wire 12v so it thinks someone is pushing in the clutch. I HAVE ATTACHED 12V TO THIS WIRE STRAIGHT FROM THE BATTERY. To emulate the auto-start, I did all of these steps but it still wont crank. WHAT IN THE WORLD AM I MISSING HERE???