#1645 4-4-2 (70-8616-250) Locomotive; no smoke, no whistle

NWOGR Forum Member

Just picked this loco and tender up at a swap meet. Seemed NOS. I checked the loco for movement and correct e-unit function on a test track, which worked fine. I didn’t think checking the smoke function would be practical without the train running for a minute or so. I didn’t check the whistle on the tender.

Smoke: I verified the switches on the bottom of the loco per the instruction manual. Started with three drops, then added three more. Nothing.

Whistle: I ran it on my FasTrack large 8 (about 35 feet of track) for five minutes using a 1033 from an early ‘50s postwar set. This setup works fine with my 2046W. The #1645 had a blower-type mechanical whistle (but not the same as the 2048 whistle). Should the 1033 work with the later tender? The instruction manual mentions “Lionel no. 610-5906-001 Sound Activation Button for activating the whistle” but doesn’t the 1033 do something similarly?

Short of opening up the loco and checking for voltage, is there anything else I could check for?

Thanks.

12/28/217:14 PM

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bmoran4OGR Forum Member

A few things:

Your locomotive and tender SKU is 6-18736
There is no 2048W... I think you mean a 2046W Tender?
The 1033 should be just fine, but you can use the 5906 sound activation button or build your own diode tree.

The classic Lionel transformers and their whistle/horn activation controls have 3 positions:

Off - No whistle
Pickup- High DC offset just enough initiate the command
Hold - Minimal DC offset to hold the whistle command active and an additional +5V Boost to for older air whistles

The modern electronics generally only react to the Pickup and not the Hold position, but experiment to find what works for you.

The Pickup position is selected by moving the whistle lever partway. Turn it just shy of the Hold position (just shy of the position that provides the 5V boost that brightens the headlight and speeds the motor).

The details of the multiple steps of the whistle/horn control are documented in the Lionel literature:

It is not uncommon for the 610-8633-010 whistle control PCB to fail. The determined sometimes replace discrete components on these boards to bring them back, but outright replacement is simpler.

The smoke unit shouldn't be run dry, but it does happen and prematurely burns out the heating element. One can check for the proper 16 Ohm resistance and replace as necessary (610-8736-200, 610-8738-200, or 610-8738-250 depending upon configuration and availability).

you should also know that the motor and electronic e-unit are relatively fragile and it doesn't help that the smoke unit may be wired through the e-unit (extra electrical load). If you do perform work, rewire it so that the smoke unit is powered straight from the track. I believe it was wired to the e-unit so that the smoke unit wouldn't heat while in neutral.

12/28/217:30 PM

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NWOGR Forum Member

Corrected (2046W)

Thanks - that helped. The whistle needs full throttle @ A&U (~15.75 VAC) but it works.

So I assume the circuit board is the electronic E-unit. I'll check for 16 Ohms at the smoke generator. Any info available on how to disassemble this loco and perform the E-unit bypass mod for the smoke generator?

12/29/2112:22 AM

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bmoran4OGR Forum Member

Here is the pictoral breakdown and parts list: https://www.lionelsupport.com/...90-933b-d6ebad87376b

Here is the basic schematic for what you want (but wire colors may differ with production variations):