ERR board light hook ups show 40 Volts?

Well, the obvious answer is, something is wrong with your measurement technique.

If you have 18 volts to the locomotive, there is NOTHING in any of the electronics on the ERR boards that can boost that voltage.

Connecting lights to the ERR boards is actually very easy.

Lighting outputs are half-wave track power in command mode and full-wave track power in conventional mode.  Typically, for incandescent bulbs, you'd use 12V bulbs.  For LEDs, use a 470 ohm resistor and an LED in series, remembering that the lighting outputs are negative in respect to frame ground in command mode.

Thanks Gun.  I actual used a previous suggestion you gave on the resistor.  I used a 330 since there is only one back up light.  It seems to be working well even with the existing lights.  The front lights are controlled in the loco itself so not linked to the ERR.

When I read the volts, I put the probes on the motor terminals on the ERR board and confirmed the 18 volts coming in.  When I used the probes on the light terminals (5 and 6) I got 39 volts on the meter???  Was that not the right way?

Thanks again!

Troy

With 18V on the track, I measure 10VAC across the lighting outputs to ground from the R4LC in command, and if I switch to DC, I get around 9VDC.  I can't imagine getting more than 18V, that has to be a measurement error.

I don't understand the 18V on the motor terminals, I hope you're putting the 18V on the correct terminals!

Ah... I meant I was reading the 18 volts on the ERR hookups for the ac hot/ ac common terminals on the side where you hook the motors.  In the end, it all worked out.  I made a small board with two 470ohm resistors.  For the rear markers lamps that I wanted on all the time, I ran those to the AC/ hot and common terminals through the 470 R.  I ran the backup light to the ERR #5 and 6 making sure to reverse the pos/neg as you noted.  Everything responds well, has perfect brightness and does not get hot at all.

Thanks again!

I'm glad you weren't putting the AC into the motor leads.

I suspect something about your meter causes the bogus readings, I've never been able to repeat that kind of reading here.