Install question for ESU Lokpilot 54688, blue wire ?

[mu26aeh]

I purchased said ESU decoder today for install in Fox Valley ES44.  I know the blue wire is the common, but what do I do with it ?  Do I need to solder with the PC board somewhere ?  Anyone have experience with these ?

[RBrodzinsky]

The blue wire is the positive common, used primarily as the positive for LEDs. But I believe the FVM boards provide the common directly from the track pickup, so you should be good to go.

[peteski]

The blue wire is the positive common, used primarily as the positive for LEDs. But I believe the FVM boards provide the common directly from the track pickup, so you should be good to go.

Just to clarify, by "good to go" he means that *IF* the FVM board provides its own positive voltage for the headlights, then you don't need to use the blue wire from the decoder - just leave it unconnected and insulated (so it doesn't accidentally touch anything).

[mu26aeh]

The lights are on the PC board, which the decoder is a 6 pin variety.

[peteski]

The lights are on the PC board, which the decoder is a 6 pin variety.

I don't have one of those locos, so I can't be certain, but I highly suspect that FVM did include  2 diodes (basically a positive half of a bridge rectifier) on their PC board to supply the "blue" voltage to the headlight LEDs.  If that is the case then leave the blue wire unconnected/insulated.  If you could post a photo of the PC board's component side, that can be verified.

[mu26aeh]

[peteski]

That makes things clearer.
No need to hook up the blue wire anywhere (make sure to leave the wire's end insulated so it doesn't touch anything).  The FVM PC board does have the 2 diodes (D1 and D2)  required to produce the "blue" voltage for the headlight LEDs. The LEDs are also have 1.5k ohm resistors in series, and capacitors to shunt voltage spikes in DC mode.  You're all set - just plug in the 6-pin decoder plug into the FVM PC board.