Lionel Locomotive 2037 Repair, headlight assembly

I'm replacing the headlight assembly (washer & eyelet 61-22) on a Lionel 20 37 locomotive. What is the power source for the headlight? I've got the NOS
washer and eyelet with 4 inch cloth wire lead but I can't figure out where to solder/attach the lead. The repair diagram makes it look like it attach es to the Truck Plate Assembly but there's no power source to that assembly . Any help would be greatly appreciated.
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On 2014-01-11 12:48 PM, snipped-for-privacy@yahoo.com wrote:

The locomotive picks up power through the the center rail pickup (slider or rollers), and through the wheels. The working parts (motor, lights, etc) are connected to both of these so that the power goes from one pickup (say the wheels) through the motor (or light, etc)) and then to other pickup (center slider), thus completing the circuit.
The headlight socket has a central nub that is isolated from the screwbase. The central nub is connected to either the wheels or the central slider, and vice versa for the screwbase. The connection may be indirect, that is, via some other part(s) that are connected to the frame (and hence to the wheels), or to the central slider pickup.
I think you can figure it out. Really! ;-)
HTH
--
Wolf K.
kirkwood40.blogspot.ca
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The headlight socket is electrically connected to the outer rails. The washer/eyelet is connected to the center rail, usually via a solder lug on the e-unit or the smoke unit, but it's ok to go straight to the pickup roller.
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