Horn blows withhout pushing the horn button

What transformer are you using?  Do you have other Lionel diesels from that era that work correctly?

Hello Tony H,  I'm using an MRC  270 watt transformer.  None of my other engines do this.  I have Other Lionel as well as MTH, RMT and Williams both steam and diesel.  George

This is normally a high-resistance connection that causes a DC offset on the track.

I just cured a Williams engine of this problem by removing the pickups and soaking them in acetone. There must have been some crud inside the rollers.

I have an old Williams EP5 that if the track is not clean will blow the horn as it runs. Clean the track and it stops. My test track a  circle of O-72  had arc pits in the center rail of three or four sections of track and when it ran over that track the horn blew.   I made a sort of track cleaning car that slides a copper plate on the center rail and burnishes it. If I run that car a while the EP5's horn does not blow when it crosses those bad sections of track.  Nothing like clean track and sound wiring connections to keep trains with complicated electronics from going crazy, or worse.  Your track and wheels cannot be too clean                           j

Thanks for all the ideas.  I will try the left post on my Pure Power Dual transformer.  I'll  also clean the pickup rollers.  If I can find a piece of copper I'll clean the center rail because it seems to happen on certain pieces of track.  Again, thanks to all of you for taking the time to reply.  George

I had a similar problem on a Polar Express Trainsounds Tender that kept blowing the whistle repeatedly.  I ultimately had to change out the sound board which fixed it.  After you do all the cleaning you signed yourself up for, next remove the sound board and then extract the sound chip using the correct tool (no picks or jeweler's screwdriver).  That can reduce resistance (corrosion build up) on the pin connectors.  The shells come off and back on these F3's pretty easily. 

Hi Steims,  I may have to replace the board but it's $45 so I'm trying all other ideas and saving this option for last.  The shell does come off easily.  I've unplugged the speaker to make the problem go away but it's not the permanent fix I want.  

I tried the  left post  on the transformer, Pure Power Dual, and the horn still sounds.

Remember to remove the board and reinstall to see if that cleans the pin.  Then try the chip if you have right tool.  

If my engine would do that predictably on a certain piece of track, that would be cool.  It shows the dedication of that engineer to his duty when I forget to push the horn button.  I would move that track to a crossing gate area.

Not cool if it's random or if every engine does it.

George Retired Msgt USAF 74-94 posted:

Hello Tony H,  I'm using an MRC  270 watt transformer.  None of my other engines do this.  I have Other Lionel as well as MTH, RMT and Williams both steam and diesel.  George

It is almost always a good idea to run modern trains with modern power sources, not only for "behavioral" reasons, but for the safety of the loco electronics, relative to power spikes and short protection - of the loco, not the transformer. The behavioral problems can be inconsistent and vary from loco to loco.

(As an exception, many "old" early modern QSI/Protosound systems required using a Postwar transformer because of wave forms, of course.)

George! if you need to replace the lionel sound board they are 50% off November 8th good time to buy  Lionel parts cheaper then normal.!

Alan