trying to get horn to work in a 2245 Texas Special

If you have access to a dc voltmeter, verify that the horn is receiving the full 1.5 volts.  You can manually lift up the lower contact on the horn relay to power up the circuit and check the voltage.  If voltage is not 1.5 volts, attach one lead to the loco chassis and start checking voltage back to the battery. Sometimes the contacts on the swivel plate or the upper spring contact on the battery bracket do not make good contact.

@Jolodo posted:

I am trying to get a horn to work in a thanks 2245 Texas.The horn works fine outside the engine. I match the electrical connections with another 2245 that works fine. The battery is full charge. I even changed out the horn relay and get  the same result. A horn that makes a low grade tick tick. I don't know what else to do.... any help would be greatly appreciated.... thanks

Wire it to a 9V battery to give the horn a workout.  Sometimes, when the horns are original or old, the 1.5 D battery doesn't have enough "juice" to get things going.  The 9V does, and for whatever reason it seems like once you give the horn a good workout with the 9v, it will work with the 1.5V D installed in the locomotive.  Good luck, HTH.

I have replaced the batteries on my Postwar Diesel horns with a 3rd party "battery eliminator".    The ones with a voltage adjustment built in.  Allows me to set the voltage to 2-3 volts to help the old contacts on the horn and relay have enough voltage to work well.  A DC voltmeter is needed to do the adjustment once installed.   There are even ones that also replace the relay. 

The advantage besides a little more voltage is you never have to worry about a leaking battery causing problems.

I have changed many of my horns to 3 volts,using AA or AAA battery's with no problems..

hanks for tip on checking battery voltage, I will try that. I also notice that the battery both 1.5 "d " cell and 9 volt add on get "very" hot and still no horn sound. What would cause this to happen?? Thanks again for any help.

Heat is high amperage, or the contacts stay connected on the horn.  When buzzing it cycles on/off fast with lower current draw.   They were not designed to run continuously no matter what my grandaughter thinks.

How do you fix a horn...  Many ways.  I go through these steps.

1 It sounds like the horn is working when you connect to the battery directly "outside the engine".   If it has gotten hot, make sure it still works this way.  Let it buzz 10 seconds or so to help clean the internal contacts.  Make sure it will buzz anytime the power is connected. 

You may need to adjust the buzzer so it starts better or sounds better, but be careful it doesn't take much! Know how far and direction you have turned the adjuster so you can put it back if needed.

2. Once buzzing well with the battery directly, try it in the engine without power.  Make sure the horn is mounted tightly, this is the ground.  If the mounting screws have not been removed, loosen and re-tighten to clear any possible light corrosion interference.  Use a screwdriver to manually close the relay.   Turning the unit upside down can do it also.  Does it buzz?  If not work the problem until it does buzz anytime you close the relay contacts.   

If you can see the relays close and only get  click, you may need to lightly file the contact points on the relay to lower resistence.  Make sure all wire connections are good.  Any resistance can cause problems. 

3. Once working by manually closing the relay, then try with power and the horn relay.   Make sure the relay stays closed when the horn button is used, not fluttering.    If the relay doesn't work, it could be bad or a problem with the horn switch in the transformer.   Does the transformer work with other "horns" in engines?

@Jolodo posted:

I am trying to get a horn to work in a thanks 2245 Texas.The horn works fine outside the engine. I match the electrical connections with another 2245 that works fine. The battery is full charge. I even changed out the horn relay and get  the same result. A horn that makes a low grade tick tick. I don't know what else to do.... any help would be greatly appreciated.... thanks

The "low grade tick tick tick" sounds like a problem with the relay - trying to close but not quite getting there.

@Jolodo posted:

hanks for tip on checking battery voltage, I will try that. I also notice that the battery both 1.5 "d " cell and 9 volt add on get "very" hot and still no horn sound. What would cause this to happen?? Thanks again for any help.

If the battery is getting hot, it sounds like there is a short somewhere in the circuit

Thanks to everyone with your tips.... I know what my project for tonight will be.....