push button start with dei viper , latch

I have a Viper mounted in my car, and I tapped into the remote start lead with a push button connected to ground...

This fires the remote start sequence and starts the car. Pressing the brake kills the remote start...Simple...

Now, I want to get rid of the key/barrel all together (have DEI immobilizer by-pass installed already) and use JUST the button.

BTW, the button is wired thru the ignition kill relay in the DEI relay pack so it's not functional when the alarm is engaged.

I have an Allen-Bradley 12V latch relay, which will close the circuit with a pulse (doesn't need constant power) and disengages the latch by reversing the polarity

on the coil...this might be a little tricky. Here is my problem...

Instead of the DEI powering up the ign/acc with it's own relay pack, it's going to trigger the AB latch instead, which in turn is hooked up to a pair of Bosch relays...1 for

accssory the other for ignition...the starter lead will remain as is, connected to the DEI module.

Now, I MUST have the DEI relay pack disengage immediately, somehow, after the car starts (currently hooked to the brake pedal), because if it doesn't, and I hit the

'engine stop', it'll short out, because the latch needs reverse polarity to disengage remember...and the DEI relays will still be applying opposite power to the latch.

Is there an output on the Viper that triggers automatically when the car starts? This would be ideal...I could just hook it to a relay, or straight into the remote starter kill lead...

Also, this AB latch needs to reverse both + as well as - to disengage. I THINK I can hook the ign. relay output of the DEI to the + latching side of the latch, and also run the same lead into a relay,

which is hooked to ground, to supply a temporary ground output to the - side of the latch?

BTW, I'm also hooking in a simple 555 on delay circuit to the start button...it'll function like this;

When you press and hold the start button for 2 seconds, it'll pulse the latch, powering up the ign and acc without starting the car. The DEI

remote start is only looking for a double pulse to fire the sequence, so it'll ignore this 2 second hold.

And again, the stop button will disengage the latch...

Here are some pic's of the button and latch...

The latch...pricey little bugger, but very reliable!

And

the push button start/stop switch

Notice the actual switches on the back. Totally modular, with up to 4 seperate switches. 2 per button...

I have 3 'normally open' cartridges mounted here. You can also use the red 'normally closed' cartridges, or

any combination of the two...