remote start, 98 ford mustang

I'm assuming your remote start/alarm system was simply not connected to the ignition system, therefore the necessary wires for remote starting were taped off (or removed from the wiring harness).

the remote starter had a heavy duty relay built into it, as well as a relay for ignition and accessory power.  Should be pretty straightforward for you to connect these wires to the Ford ignition, starter, and accessory wires.  You have two ignition wires, so you can use your 40A 12volt relay to power that second ignition wire off your first ignition wire, solving that problem.  However, this may not be necessary as many remote start brains have an auxillary (or two) wire to power 2nd ignition/2nd accessory/2nd starter, etc.

You can not add a "remote start" to an alarm that simply...think about it...you use an output of the alarm to energize that relay to crank the car..then what? How does the relay know when the vehicle is running?/  It doesn't. And what about powering up the ignition?? you need that for the car to run as well. What about the HVAC? You want those to power up as well so the interior is warm in the winter and cool in the summer when you enter it..thats the purpose of a remote start..right?

If installing a remote start was as simple as adding a relay to an alarm output that would make an installers life easy..but unfortunatly there is more to it.

You need to purchase an "add on" remote start module..or some "stand alone" systems as well have an activation wire that can be used with an exisiting alarms output. Now there are ways to make a simple remote start using just relays, caps and diodes but it is much safer, relaible and simple to use a module.

Good luck and if you have any other questions just post.

you will also have to connect the tachometer wire and brake wire for your remote starter feature to properly work.  What make/model of remote starter is already installed in the 'stang?  I'm assuming that if it has an output(s) for remote starting, that it has the necessary circuits and relays built into it to allow for remote starting.  Not sure I've ever seen an alarm system that allow and add-on remote starter. 

No .. it still won't work the way you want it to --

You still aren't clear about what your alarm has built into it .. is or isn't there a remote start feature on your alarm brain?

Now, I'm assuming there is not, just an auxillary output that could trigger an add-on remote start unit as suggested by custom audio ny.

Yes, in theory you could use a negative pulse aux output to trigger a relay to connect 12 volts to the starter wire and when you "hear" that the car has started, you can LET GO of the button to stop it from continuing to crank -- kinda like what you do with a key in the ignition barrel every time you start a car.

However, after the car has turned over, the ignition and accessory wires need constant power.  So you need two aux (-) outputs from your alarm brain that have two separate button triggers: 1) first, you'll have to press the ignition button to send 12 volts fused constant power to the ignition and accessory wires.  2) then, you next will press and hold the "start" button on the keyfob to start your car.. and you'll have to let go after you hear the car successfully turn over.  3) when you get into your car... you'll have to put the key in the barrel, and turn to the III position (on/run position) and then press your alarm keyfob button to DISCONNECT the 12 volts fused constant power from the ignition and accessory wires so that when you're done driving around, your car will shut off w/ the key.  Otherwise, the car will continue to run after you've taken the key out.

Again, does your alarm brain have a remote starter built into it?  What is the make/model of the alarm? Hard to help w/o this information.

Or..you can use a latched output to a relay, press the remote and have it crank the starter until it burns out...but ...still..the car won't start....lol

Kidding around but hey...the question is valid for someone who does not really work on cars but understands what a relay can do. In a sense you were on the right track with your thinking...a remote start is really not much more then a bunch of relays... however, as stated before a way to monitor when the vehicle has actually started as well as monitoring RPM's and shutdown times etc is just something a simple SPDT relay will never be able to do.