HOUR METER

trey · Post by **trey** » Wed Mar 03, 2004 8:47 pm

Is the hour meter on a B2A operated off oil pressure or electrical? Mine stopped working and it seems to operate off a pressure switch. If so does anyone know how to check the gauge to see if it is bad or if the pressure switch is bad?

Ron Spiker · Post by **Ron Spiker** » Thu Mar 04, 2004 7:18 am

My meter doesn't start running until up collective, when the micro switch gets released. Mine stopped last year when one of the wires coming from the micro switch to the meter had come off.

jwgood · Post by **jwgood** » Thu Mar 04, 2004 7:55 am

There have been a variety of techniques used to operate the hour meter. Like Flylow, I have seen them activated when collective is pulled. I have also seen them activated when the oleo landing struts extend after lift off. And the most common technique used, as the factory installs them, is to be activated by oil pressure from the engine. With this being said, it's basically a debate over how to log time on components. It's very easy to test the hour meter, simply remove the wires and run a hot and ground to the terminals. Be sure to check the polarity and then simply wait six minutes and see if she ticks off some numbers. Some hour meters have a black and white alternating color scheme to let you know that they are working. As for testing the pressure switch, you can use a voltmeter set to DC voltage. Find the hot wire that goes from the Circuit Breaker panel to the oil pressure switch, there should be Battery voltage going through that wire with the battery on. Next, find the switched hot wire, which will be the positive wire leading to the hour meter. There should not be any voltage with the engine off. Next start the engine, ensuring that you have oil pressure, and take a look at the volt meter to see if at least battery voltage is being displayed. Then you should have a good idea whether to continue tracing wires or start replacing parts.

Happy hovering!!!

trey · Post by **trey** » Sun Mar 07, 2004 8:49 pm

I appreciate the help guys, but let me tell you what I found to be my problem. To start with I also had trouble with my fuel gauge not working while in flight or at operating RPM along with my hour meter not working. For the record I have the oil pressure switch which runs the hour meter. The pressure switch had an area grounding itself out causing the breaker indicating "fuel" to pop. Once I fixed the dead short my fuel gauge worked along with my hour meter. So the breaker was getting hot and popping causing no fire to get to the fuel gauge or the hour meter.