Factory Horn Hookup

I have a 2003 Chevy Silverado and it has a factory secutriy package on it. Does anyone have a schematic of how to hookup up my Nathan KL3A train horns so I can release my solenoid with the horn pad on the steering wheel. I have it hooked up to a switch right now…

Find your factory horn wires, determine which wire is the hot wire with a tester while you push the horn, tap into this wire with a jumper and run it into a toggle switch and then run it to the solenoid. This way you can honk your horn normal, or flip the switch and the train horn will blow when you depress your steering wheel horn. We just did this to member Bixby1980’s Conductor Set this weekend.

Looks like a black wire in your steering column that puts out a negative signal when activated, so you’ll power the valve constant 12v and tie your toggle switch into the black wire on the valve, and then the black wire in the column. Good luck!

| 12V|red (x2) |+ |ignition harness |
| STARTER|yellow |+ |ignition harness |
| IGNITION|pink (12 awg) |+ |ignition harness |
| SECOND IGNITION|white |+ |ignition harness |
| ACCESSORY|orange |+ |ignition harness |
| SECOND ACCESSORY|brown |+ |ignition harness |
| POWER LOCK|use Directed module | | |
| POWER UNLOCK|part #456G *2 | | |
| LOCK MOTOR|gray | |driver door module in door |
| UNLOCK MOTOR|tan | |driver door module in door |
| DISARM DEFEAT|tan | |pass. door module in door |
| PARKING LIGHTS -|gray/black | |brown plug @ BCM *1 |
| DOOR TRIGGER|gry/blk(L),blk/wht(R|- |each door module in door *3 |
| DOME SUPERVISION|use door trigger | | |
| HOOD PIN| | | |
| FCTRY ALARM ARM|arms with lock | | |
|FCTRY ALRM DISARM|lt. green |- |driver door module in door |
| TACHOMETER|NOT pnk, blk, or brn| |any ignition coil |
| SPEED SENSE| | | |
| BRAKE WIRE|white |+ |brake pedal switch |
| HORN TRIGGER|black |- |steering column |
| WIPERS|pink |- |steering column |
| LF WINDOW UP/DN|blue - brown |A |driver window motor |
| RF WINDOW UP/DN|blue - brown |A |passenger window motor |
NOTE: This vehicle has the passlock II immobilizer system that, when adding a remote start, must be interfaced with. Use DEI part 555t or 555L. The passlock II wire colors are yellow, black, and red/white (not used). *1 The BCM (Body Control Module) is under the driver side dash. *2 If Directed module part #456G is not available, refer to directfax document #1601. On base model trucks the lock wire is lt. blue (-) and unlock wire is white (-). They are in the lt. blue plug at the BCM. *3 On base model trucks the door trigger wires are in the lt. blue plug at the BCM. On 4dr trucks the LR door trigger is lt. blue/black, and the RR is lt. green/black. They are in the purple plug at the BCM. Use all wires and diode isolate.