horn does not work on postwar Alcos; Need help

Hello.

The quickest fix 'Try" I can think of,is to set up a few pieces of straight track,take off the shells,put the batteries back in the horns,check all of your solder connections to make sure that they are not the problem.

Then,with the train e-unit in nuetral position,turn the track power all the way up.Make sure that the horn 'RELAY" is making contact,when you hit the horn button on the transformer.You may have to adjust the contacts so they meet up.

And also try to spray a little CRC Electronic cleaner into the horn relay contact points.

PHYSICALLY hold the relay so it is making contact,and try 'TAPPING" the horn with the wood or plastic end of a screwdriver.

They should  start to make somekind of sound by then.

Also,you can give the adjustment screw on the bottom of the horn a turn with the screwdriver.After these things have been in storage awhile,it can take a little doing to get them working reliably again.

You can also 'polish' the horn contacts with a piece of 1000 or higher wet or dry sandpaper to remove any oxidation that might have accumulated on the contacts while they were in storage.Do this with the DRY sandpaper.

If all this fails,message me back,and I will tell you how to SHOCK the horn back to life with a battery.But hopefully,these other maintenance tips will get the horn going for your grandkids.By the end of the day,I will help you get those horns working.

Happy Holidays,Kenny

If you don't have the very fine (1000 grit) wet/dry sandpaper that Ken recommended, you can use an index or business card.
I like to wet a section of the card with contact cleaner or pure mineral spirits to clean the contact.

Follow using the wet section with using a dry section of the card.

Another trouble spot is the electrical path from the relay body to the relay armature (part that moves up and down). Sometimes I solder a couple of strands of wire from the back of the relay body to the bottom of the armature.
If you need to do this, be certain to leave enough slack to allow the armature to move freely, and use very little solder. I use one or two strands taken from a piece of 18-22 gauge stranded wire.
Plus one must make certain the wire isn't touching anything it shouldn't.

Thanks for the great instructions guys. As soon as I get our Thanksgiving guests fed and on their way home, I will get the engines on the workbench and try these fixes this evening, or tomorrow.

Jeff

I'm not a fan of using an abrasive like sandpaper on relay contacts - using an index card that has some CRC electrical contact cleaner (plastic compatible type) and gently sliding the card between the contact points almost always does the trick and doesn't rough up the surface of the contacts - the contacts are delicate so work carefully.  Another approach is to use Simichrome polish and the index card trick first - you will be amazed at the black gunk that will come off the contacts.  Once the card stops coming out black, use the CRC contact cleaner/card step to remove any traces of the Simichrome.  You can find Simichrome at Amazon (best pricing), on Ebay, and antique malls usually have a couple booths selling it.  You can also give the horn a cleaning with Simichrome as well, being sure to get the part of the horn bracket that rests on the chassis. 

I'd hold off on adjusting the set screw until you've cleaned all the contact areas first.  A lot of horn/whistle problems are due to poor ground being made.  I always use a bit of contact cleaner on a small rag to wipe down the chassis.  Make sure the area the horn is attached to is also cleaned up with contact cleaner.  Sometimes a jolt from a 9 volt battery will wake up a balky horn.  Use alligator clips to get the juice from the battery to the horn.  Don't leave the battery connected for long.

Got the horn on both units working, using the CRC cleaner and a business card. A little cleaning did the trick. My grandson can can't get enough of those horns. Thanks for the help guys.

Jeff

Thank you for letting us know how you made out.

C.W.- Very good tip about using the business card.I am home from work with broken ribs.-Now everytime I don't have to use that confounded sandpaper!!!!-Thanks.I learn something everyday from this forum!!!!Now,if someone would just teach me how to fix these new ones....