Re: Adjusting 32's horns

Posted by 32model901 On 2010/12/31 8:32:56

Tbirdman,

If you have or can borrow a digital voltmeter you may want to check the resistance of the coils. Set the meter to a low resistance scale and measure the resistance of the coils. A good coil is going to measure around 4 ohms.

The difference in current draw could be due to a shorted winding in the one of the coils, or it could be because the points are not functioning properly.

If you apply current to the good horn the center core is going to pull down and open the points up. When the points open the core will spring back, closing the points. This rapid movement of the center core and diaphragm makes the sound.

The rapid turn on / turn off of a good horn will show a different current draw on your power supply compared to a bad horn where the center core doesn't move, and the coil is energized 100% of the time.

Regards,

Dave