scytek astra 4000rs on a 2005 scion xb

Hey Friends I have a couple questions that I hope that you guys can help me out with. I'm installing a Scytek Astra 4000RS on a 2005 Scion xB. Not sure where to put these wires. Pin 1 BROWN / white: Horn Output (-) 500 mA. Connect to a relay to activate the vehicle’s horn when the alarm is triggered. (The wiring info says horn trigger (-) WHITE/ red at harness at steering column; Do I need to use a relay? Both wires are negative. I found two WHITE/ red wires. One is a single wire in a harness next to (I assume) the yellow wire airbag harness right under the steering wheel. The other is in a harness with about 8-10 wires over near the wiper and ignition. Which one do I connect to? Pin 4 Green Negative Door Input (-), Connect to the door switch circuit wire that shows ground when the door is open. Pin 5 Violet Positive Door Input (+), Connect to the door switch circuit wire that shows +12V when the door is open. (The wiring info says door trigger (-) RED / white at harness on top of fuse box.) That's for the negative input, where do I put the positive input wire? Also, I'm not sure what harness. It's not specific. Pin 7 WHITE/ black: Hood Pin Input (-). Connect the to the hood pin switch. The switch must provide a ground output when switch is opened. I have the hood pin switch installed and connected, but it doesn't seem to work (weak connection or do I need to diode isolate?) Sorry if these are silly questions. Thanks in advance for your help!

No relay needed for the Horn connection.  As far as which wire, you really need to test.  You should test every

wire prior to making the connection.  Car computers are getting expensive.

While the 4000RS system provides for either a (+) or (-) Door Trigger Input, you only need to use one.  Your car

has (-) triggers, so that is the one to use.

Actually the Hood Pin Switch should provide a Ground signal when the hood is opened.  This (-) input prevents

the engine from remote starting.  As long as you screwed the hood pin into solid frame metal it should work ( fora year or two before it rusts ).  No diode needed.

The best way to  check for a (-) signal is with a Digital Multi Meter.  Connect the Red test lead to a +12V constant

source and the Black test lead to the suspect wire, like the WHITE/ Red Horn wire.  When you press the hornbutton, the DMM will go to +12V.

Soldering is fun!

Thanks for your reply and advise kreg357. Hopefully I can work on this tomorrow. I'll post my results after. Thanks again!

Getting ready to try this,I remembered that the wiring info here says. Door Trigger, RED / white (-) top of fuse box (9 pin plug) Dome Supervision - use door trigger wire Pin 9 BLACK/ white: Dome Light Output (-) 500 mA. Connect to the wire that activates the vehicle’s dome light, usually the door pin switch wire. (see Green and Violet door trigger wires). Note: Must Use Relay. My question is can I connect the (Green Negative Door Input (-) from the alarm to the door trigger wire RED / white (-) when I already have the dome light BLACK/ white wire connected to it? Do I need a relay?

Do you need the Dome Light Output connected?  Most newer cars will turn on the dome light with an unlock command.  Think I would not connect this wire unless it was needed.  Once the 4000RS is installed, test it by using the 4000RS FOB to unlock the doors and see if the Dome Light comes on. 

Also use your DMM test procedure to see if the RED / White (-) Door Trigger wire is monitoring all the doors, not just the drivers door.  You are installing an alarm system and it should monitor all the doors and hatch.

Soldering is fun!

Not sure if I need it connected. Ah, good to know. Ok, I'll give that a shot. Ok, will test it.

Ok, Everything works great! I tested the WHITE/ Red Horn wire and that checked out, so I connected the BROWN / white horn output wire. Disconnected the BLACK/ white dome light output wire and tested with the key fob, interior lights worked fine. So I then connected the green negative door input from the alarm to the door RED / white trigger wire. The hood pin female wire connector wasn't seated fully. So reinstalled the pin and wire. Tested everything out and it works great! Thanks kreg357 for all your help, I knew I could rely on the pros at the 12volt.com!

update: So I went out to run a quick errand and noticed my "open door warning light" was on. When I opened the door it got brighter, when I closed the door it dims, but stays on continuously. I double checked that the doors and hatch are shut all the way and it's still on. The alarm and car seems to function fine, btw. Any suggestions on why it could be and how to get it back to normal? Thanks in advance.

As a test, temporarily disconnect the 4000RS (-) Door Trigger Input wire from the vehicles RED / White wire.Does the "Open Door Warning Light" return to normal operation?  If yes, then that was the problem.  Youcould try installing a 1N4001 diode ( band towards the vehicle ) in the Pin 4 Green Negative Door Input (-) wire and re-connect it to the vehicles RED / White wire.Soldering is fun!

I disconnected the (-) door trigger input wire from the RED / white wire and it went back to normal operation and the light went off. I'll pick up some diode's from radio shack tomorrow and report my progress. Thanks for the tip.