Need a wiring diagram

PeterA-

The 8152-050 board is common to many diesels with an operating horn. The black wire is ground, and the red wire connects to the third rail rollers; the two pins connect to the speaker.

There are a few possibilities why the horn may not be working.

1. The sound activation button may be wired backwards to the track. When pressed the button adds a DC voltage to the tracks, causing the horn to sound. Since DC has polarity, wiring the button backwards will output the wrong polarity voltage (either negative DC or positive DC; I forget which). Interestingly this is why locomotives with a horn/whistle and bell require two sound buttons; one button provides the right DC voltage to trigger the horn/whistle, and the second button (being wired backwards per the diagram) provides the opposite DC voltage to trigger the bell sound.

2. The speaker should be rated for 16ohms; using an 8ohm speaker can result in damage to the speaker. Try testing the board with a different speaker.

3. The speaker is connected backwards; try reversing the leads on the board.

4. Poor connections - as these parts are very old (even new/old stock), it is possible that the connections need to be cleaned/polished to ensure good connectivity. Also check for broken wires or cold solder joints.

Hope this helps!

-John

@PeterA posted:

...on neither one can I get the horn to blow with power connected to the leads and an 8ohm speaker to the terminals..

By chance, are you using a whistle/horn controller? Which one?

Hoping to use the postwar whistle control on the 1033.  Will this operate only off the MPC horn button?

@PeterA posted:

Hoping to use the postwar whistle control on the 1033.  Will this operate only off the MPC horn button?

If you wire them to the track as suggested by Lionel, either old (1033) or new (MPC Era) transformer will work.

However if you inadvertently wire them to the track backwards, i.e. leads reversed, then the "whistle/horn" button effectively becomes a "bell" button instead.  Since your horn board doesn't have a bell function you'll hear nothing in this situation.

Mike

@PeterA posted:

Hoping to use the postwar whistle control on the 1033.  Will this operate only off the MPC horn button?

It will work with any properly working whistle controller.  The 8251-50 controller was a disaster, don't bother with it. Use 5906 instead.

Don't forget, with the board connected red to center rail rollers and black to chassis ground, the 1033 will blow the horn only with "U" connected to lockon clip 1, "A"(or B) connected to lockon clip 2.

@AcelaNYP posted:

2. The speaker should be rated for 16ohms; using an 8ohm speaker can result in damage to the speaker. Try testing the board with a different speaker.

3. The speaker is connected backwards; try reversing the leads on the board.

-John

2. using a speaker with a lower impedance can damage the amplifier, which could also result in damage to the speaker.

3. A speaker that is wired backwards will still produce sound. The only caveat is that multiple speakers wired with different polarity will have cancellation issues mostly in the lower frequencies.