MTH Steam Light Bracket Polarity

If neither of the wires are going to the frame, you're good with either polarity, it's an incandescent light bulb, it doesn't know from polarity.  If either wire is grounded, you have to fix that first, both MUST be isolated from the chassis.

@gunrunnerjohn posted:

If neither of the wires are going to the frame, you're good with either polarity, it's an incandescent light bulb, it doesn't know from polarity.  If either wire is grounded, you have to fix that first, both MUST be isolated from the chassis.

No continuity between the bracket and either of the wires means I’m good, right? I checked that as well and all appears to be good.

Edit: Just cut off the connector and stopped the ends of the wires. I tested it with a AAA battery and got a dim glow out of the bulb.

Yep, the purple wire on that should go to the purple wire in the harness, but if it doesn't, no harm, no foul with an incandescent bulb.  The bulb is a 6V bulb FYI.

@gunrunnerjohn posted:

Yep, the purple wire on that should go to the purple wire in the harness, but if it doesn't, no harm, no foul with an incandescent bulb.  The bulb is a 6V bulb FYI.

That’s what I thought but just wanted to be 100% sure. Can’t quite afford a dead board right now. Thanks!

So I ordered a wiring harness from MTH with an 8 pin 5v connector with a single wire coming off pin 3. From wiring diagrams, I've read this is the ditch 1 connection and I know the marker lights are on the ditch connector from looking at the engine's sound file.

I spliced and soldered the wires appropriately and checked continuity and all looked to be good with no shorting to the chassis. When testing however, nothing. The engine still turns on just fine and everything else works, but the bulb for the markers will not light up, even when turning off and on the LMK softkey. I tried two separate 6v bulbs and re-checked the continuity of the bulb socket and the wires and all is still good.

What may I be doing wrong? The board is a 3v PS2 board with 5v connectors. Are these boards any different by chance as far as pinout goes?

The 3V board with the 5V connector shells is the exact same board as with the white connector shells, and the pinouts of the 3V and 5V boards is the same anyway.