Skip to main content

     I have tested three Lionel tenders on my layout. I run them on an oval of track with a ZW transformer. When I throw the throttle to start the steam loco (a postwar #736 or 685), the whistle relay activates, continuously sounding the whistle as the train operates. Is this a transformer issue or a tender issue. The whistle should operate only when pushing the whistle button, not the throttle.

Thank you for your assistance,

JohnKorajczyk

Original Post

Replies sorted oldest to newest

The whistle relays should not activate with the ZW throttle being moved. It sounds like the whistle button may be stuck. Try hooking up the track to the opposite throttle and see what happens. If the whistles still blow, you have a DC voltage somehow getting to the track.  Get a voltmeter set to DC volts and see if there is a DC voltage on the track with the throttles on.

 

Larry

A much simpler test would be to swap throttle channel - if you are using A-U to power your troublesome track, try using D-U to see if it behaves the same. If it behaves differently (and correctly), you'll know for sure that the whistle circuitry for the initial throttle channel at fault. At that point, you can use the ZW service diagrams that Olsen's kindly hosts as well as @Tranz4mr's awesome webpage and inspect/replace the circuitry such as the whistle diode or rectifier plate. You might as well also follow up and checkout the whole transformer too!.

As an aside, Olsen's also has tender whistle service diagrams too, but I initially suspect your fault does not lie within.

 

Last edited by bmoran4
@Rob English posted:

Relay can be stuck in closed position.

 

Definitely a well known issue, but to have it happen on 3 tenders concurrently would be a statistical anomaly in my experience, hence my suggestion to look at the transformer first... Also, initially swapping the ZW throttle channels to the track requires no tools or opening anything up and can narrow things down.

Besides the valid issues with ZW whistle switches stated above tender and diesel whistle relays can have issues too. It seems sometimes the contact plate that pulls up in the whistle relay can get magnetized and stick. One suggestion is to add a piece of non conductive tape to the bottom of the magnetic coil between the contact plate and the bottom of the coil. Sometimes this helps sometimes it doesn't

Try it with 2 batteries to give you 3 volts dc.  The relay should close. Then try it with 16 volts ac. The relay should not close. More of a problem with whistle relays is getting power through the contacts that control the whistle motor or horn. If you take that screw out that holds all the terminals on, you can drop out the fixed contact. This gives access to both the fixed and movable contacts for cleaning. On a prewar or postwar relays the contacts are coined silver. Polish then with something not too abrasive. The other problem is the hinge joint at the back of the moving contact. I have soldered super flex wire across the hinge to take care of that problem.  This is also a good time to put a single layer of scotch tape on the end of the pole piece. This usually puts an end to relays failing to open. Take a picture of the contact stack before you take it apart, so you can get it back together in the right order.

Add Reply

Post

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
800-980-OGRR (6477)
www.ogaugerr.com

×
×
×
×
Link copied to your clipboard.
×
×