I run many conventional locos and postwar horns. All my other engines, horns and whistles work well. I have refurbished and tuned up many. I have one problem child. I am running conventional through a Legacy powermaster.
I have a postwar Santa Fe 616 (Corrected) with horn. The one that used a C battery. I have worked on this many times and the horn was never reliable. The previous owner had installed a new horn that was not lionel. I thought a battery replacer with a little higher voltage would help. It seemed to test fine, but while running, not reliable.
So I finally gave up and put in an electronic diesel horn and speaker I had. Tested worked fine, running not worth spit. The problem still exists!
I noticed that testing with the 3 position e-unit off, the horn worked fine. With e-unit on, not working. This is in nuetral, train not moving.
The E-unit is interfering some how. When I use the horn button, the E-unit gets a new hum. It is a noisy E-unit to begin with. The pawl would shake, not up and down, just shakes. It was the same hum I would hear when the horn didn't work. I thought it was in the horn originally. It is clearly in the E-unit.
The ohm rating for the E-unit matches the specs at 12ohm. No apparent short.
I found in my tech books the E-units were randomly wound and tension may have varied. Has this caused a weird reaction in this unit?
I tried to put the E-unit on DC with a full wave bridge rectifier, That seem to fix it, but not for long. At lower speeds the E-unit seemed ok. I cranked it up to max 18V for about a minute, Grandkid/heavy load setting. The e-unit got hot and I didn't want to see how hot it would go. Bag the DC fix.
My best guess now is to replace the E-unit. If that works, trash the coil in this E-unit.
Any other ideas?
