Ignition 3

IGNITION------pink                |+  |ignition harness            |
SECOND IGNITION---white          |+  |ignition harness            |
THIRD IGNITION-----pink/white      |+  |ignition harness            |
ACCESSORY-------orange              |+  |ignition harness            |

The 3rd ignition powers up the stuff that doesn't require power during remote start like wipers, radio, etc. This is much like the BROWN wire on some of the newer Chevy trucks. The WHITE wier is a MUST to connect because it will control the transmission computer and if not powered up it will send a CHECK ENGINE error on the dash.

I just had that happen! Forgot to hook up the 2nd ingition and boom service engine light. My best advice is to hook them all up, that way your safe!

I'm working on a 93 Silverado and it doesn't have a white wire (IGN 2) at the ignition switch. I've connected the orange from the Matrix RS to the orange (IGN 3) at the ignition switch. Likewise the pink from the RS harness is on the pink from the ignition switch and both reds are in place.

This leaves the 2nd iginiton (pink/white) wire from the RS harness without a connection. Do I connect it to the brown ACC wire at the ignition switch, find anotehr ignition wire elsewhere or leave it disconnected?

The 1993 does not have a second ignition wire. It has only one ignition and 1 accessory wire. Here is a wiring diagram for the truck:

|       ITEM      |     WIRE COLOR     |POL|       WIRE LOCATION        |
|              12V|red                 |+  |ignition harness            |
|          STARTER|yellow or purple    |+  |ignition harness            |
|         IGNITION|pink                |+  |ignition harness            |
|        ACCESSORY|orange              |+  |ignition harness            |
|       POWER LOCK|lt. blue            |*1 |either door boot            |
|     POWER UNLOCK|BLACK/ red           |*1 |either door boot            |
| PARKING LIGHTS +|brown               |   |switch or fuse panel        |
|       HEADLIGHTS|yellow              |+  |at switch                   |
|     DOOR TRIGGER|white               |-  |light switch                |
| DOME SUPERVISION|use door trigger    |   |                            |
|       TACHOMETER|white *2            |   |ECM *3                      |
|       BRAKE WIRE|white               |+  |at brake pedal switch       |
|     HORN TRIGGER|black               |-  |at column                   |
|           WIPERS|purple              |+  |steering column             |
|  LF WINDOW UP/DN|dk. blue - brown    |A  |at drivers door switch      |
|  RF WINDOW UP/DN|light blue - tan    |A  |drivers door or boot        |
|  LR WINDOW UP/DN|green - purple      |A  |drivers door or boot        |
|  RR WINDOW UP/DN|lt. grn - pur/wht   |A  |drivers door or boot        |

Notes:
*1 5 wire (type C) on the two door models, and positive trigger (type A) on the four door and keyless entry models.  *2 Tach wire on the 6.5 Diesel is white at the instrument cluster. Diesel wait to start wire is dk. blue (+) located at the instrument cluster.  *3 ECM located behind the glove box.

   whats the effect of not hooking up this wire? I mean does the truck sit there running and the radios is not on or what?

 I have a blazer and hooked up all 3 igns so I have no experience on the issue. I'm currently looking to install on a 2001 Silverado and probably want the radio to turn on.