1992 jaguar xj6 negative ignition

I'm in the process of installing a Viper 5204 in a 1992 Jaguar XJ6. I have the alarm portion of the system wired up, including:

-Door Lock/Unlock
-Dome Light Supervision
-Door Triggers
-Trunk Trigger
-Motion Sensor
-Tilt Sensor
-Factory Comfort-Closure Feature
-Trunk Release
-Parking Lights

All is good with the alarm with the exception of the Ignition 12v+ source used to turn off the LED, reset the tamper siren, and turn on/off the dome light. This alarm/remote starter uses the heavy gauge ignition wire to feed the circuit when remote starting but also to sense when the ignition is on for the alarm as well.

Now that I'm trying to wire the remote starter portion up, the issue is that this car uses on-board relays (accessory, ignition and starter) which are energized by grounds at the ignition switch.

Can I use H2/10 (200ma (-) Ignition 1 Output), H2/18 (200ma (-) Starter Output), and H2/22 (200ma (-) Accessory Output) to feed the wires right at the switch? This would keep the car protected by the neutral safety switch, which is between ground at the ignition switch and the starter relay coil. It would also keep me from having to run heavy gauge wires to the passenger side of the car.

If I do this, I will still need to run at least the single H3/1 Heavy-Gauge Ignition Input/Output wire for the alarm's ignition-sensing function. But if I tie this Heavy-Gauge wire into the small-gauge Ignition 12V+ wire at the ignition switch, won't the remote starter try to feed that circuit when trying to remote start? Or will it not output 12V+ as long as I leave the Heavy-Gauge
Red Battery 12V+ wires disconnected?

Thanks,
Nick

I never did get to try working on one of those cars, ever. I remember reading the tech sheets for them, though.

I would think that if the wires at the ignition switch are small, thin, low-current wires, using the negative outputs from the system should probably work.

If they're thick wires that seem to carry a lot of current, you could use the negative outputs from the system to trigger a bank of relays, and then the relays would apply chassis ground (from the car) to the ignition wires.

And you're right, you do need to have the main ignition hooked up to something so the remote starter/alarm "knows" when the ignition is on.

Just try to find some wire in the car, any wire really, that shows positive power when the ignition is on. Connect the remote starter's main ignition wire there, but be SURE to put a diode inline so that the car can feed signal to the remote starter, but NOT the other way around.

So, you should have it like this:   RS ignition wire----diode band side-----diode black side connected to car.

If you can't find any ignition wire anywhere in the car at all, you could always take the negative ignition wire from the key switch, have it activate a relay, and then the relay sends 12 volts into the remote starter.

Howie II probably did a bunch of them...

-------------
Soldering is fun!

Thanks Chris,

The car had a dealer installed Jaguar alarm system, so I used the Jaguar splice harnesses to make my connections to the car. These harnesses have the wires for battery, ignition, ground, horn, headlamps, door locks, trunk trigger, door trigger. I just cut off the Molex connector ends and splices them to my Viper harness. That's where I'm getting the ignition source.

I just wanted to make sure I'm not feeding that circuit with high current meant to start the vehicle.

The wires at the ignition switch are all low-current, which provide ground to enable relays on the passenger side of the car, under the dash. It's a bit more convenient to run these small-gauge wires right to the switch (and I have a splice harness there too, for easy wiring) rather than running these heavy-gauge wires to the output of the car's starter, ignition and accessory relays. Doing this would also bypass the car's factory Neutral Safety Switch, which interrupts the ground path between the ignition switch and the starter relay.

I'll be sure the diode isolate the ignition wire. What rating diode would I need to install here?

Thanks again for the help

Nick