Whistling tender on Polar Express Berkshire

You are missing the "ground straps"- copper axle wipers which provide the "ground" path. The axles/ wheels are insulated from the sideframes by the bearings, so no electrical path exists without the wipers or an equivalent arrangement. Something like 9536-59 or 9050-156 or 9638-65 or 8056-T82. I am not sure which (if any) is most appropriate for the particular trucks on the tender.

The slots let the air/ sound out when the whistle is in operation. 

Ok, that makes sense. The seller said the whistle had been disconnected (it was being run on 12v dc) so it sounds as though the seller lost, or discarded the wipers. 

Do you have a picture or part number? I’m trying to google and just getting a blizzard of semi-unrelated stuff. Are they just copper strips, linking the small screws (which I replaced, they were detached when I got the loco) with the axle? If so I could fabricate them, if I can’t source them 

Ok, I see. They look simple enough to fabricate to fit - what are they, 0.3mm copper strap? 

Before you go thru with the good solution of copper straps, you could cobble up some jumper wires to the axles just to make contact to see if the tender functions work.

Good call! Temporary pickups made from 0.040” phosphor bronze wound banjo strings.. 

No go. There is definitely a circuit, I can see it with the multimeter, but no response from the tender either with, or without the loco. Reversing the wires on the transformer terminals doesn’t seem to have any effect. 

Trying another whistling tender on its own, seems to work normally. 

Operating the whistle lever seems to increase power to the loco, and (at times) operate the reversing mechanism.

I must get a rolling road set up, so I can run the loco for more than a few seconds. 

Yeah, the whistle lever/button boosts voltage to the track.  Postwar tender whistles are power hogs.    With modern solid state reversers,  letting off the whistle can fool the reverser into thinking the power is off, thus activating it... 

Might wanna pop the shell and check the connections to the whistle board itself.   There's also a fix for the board itself involving clipping a resistor;  I think @gunrunnerjohn can give you the details...

Mitch

I’ve checked inside the tender and there are no obvious loose connections. I do suspect that I need to get a rolling road set up, or a test circle so that I can run the loco for more that a few seconds, I might well learn something that way. 

Here is the parts list - the loco is from set 6-31960   Tender only parts #24 is the wiper

Here is the set link for 6-31960 in case you need loco parts

The wiper is the common or outside rail of the AC the roller is the hot or AC positive

I’ve ordered some phosphor bronze strip, used for loco pickups. 

Meanwhile I’ve paired this loco with a postwar tender which I’ve cleaned and oiled the motor, sounds and looks quite good!

Rockershovel posted:

I’ve ordered some phosphor bronze strip, used for loco pickups. 

Meanwhile I’ve paired this loco with a postwar tender which I’ve cleaned and oiled the motor, sounds and looks quite good!

That is one way to solve it! Steamies just need a tender

The puffer will smoke ok - switch it off if you don't have smoke oil in it. Servicing the smoke unit will help some - try and see if you get smoke.

The smoke unit does work, but I have it switched off at present