I’m trying to restore a 6403B bell ringing tender to its original operating state, cosmetics notwithstanding. My initial problem was/is finding a wiring diagram for this one (or a 2403B or a 2203B.) I have searched the pages here and found discussions that talk about a wiring diagram, but have yet to actually find one. The previous owner had everything rewired to exclude the ringing bell circuit, so I am trying to determine the original wiring to the bell solenoid and especially the bimetal strip that serves to trigger the bell at regular intervals.
When first opened, I found both ends of the nichrome wire disconnected – the wire was wrapped around the bimetal strip, and some of the insulation that separates the two was missing. I decided that the nichrome wire needed to be reattached as follows: end near bimetal strip contacts – nichrome wire gets soldered directly to the bimetallic strip. Not an easy feat, nor is it recommended, but you deal with what you have - I suspect this wire was probably crimped under the contact rivet when new.
At the opposite end, near the bimetal strip mounting post, I attached the nichrome wire to the ungrounded end of the bell solenoid via jumper wire. This arrangement puts the nichrome wire in series with the bell solenoid, and provides an interruption in current flow to the bell when the bimetal strip is in the heated or open position.
This actually works, and provides a semi-regular frequency of bell rings, at least as good as a bimetal strip can provide – about one ring per second. The rings are not very loud, even at 14 volts, but they are reasonably regular. The problem is that Lionel would never have done things the way I just did.
Does anybody have this tender and a camera, and would be willing to open it up and photograph the bimetal strip to show where the connections are made? Or even just describe how the wiring is supposed to be?