Flyler Posted March 5 Report Posted March 5 Hello Mooney people. I have a 1979 M20J and am not sure how "flat" I should expect the voltage readout from my JPI 700 to be. The battery and alternator (plane power) are about 6 months old. The VR is the "Electrodelta VR14". I was originally suspicious of the voltage because it seemed a bit low when charging. I have an "aux avionics" switch and figured I should get familiar with it. When I flicked the switch, the JPI voltage went up nearly .5VDC. "That's not good" I thought. Then a few cycles of the avionics switch later, all on the ground thankfully, no juice at all. Replaced the avionics relay and now I have full panel voltage. Engine always cranks nice, no issues with electrical system have been noted. However, there are still some minor "steps" in the JPI voltage graph that do not coincide with flap/gear or any electrical loads. Perhaps this is just normal of an older VR. What does the braintrust think? Is this a sign of an old and tired VR, or just a sign of how the older tech VR's work? RTTAQA: 7:36 Before replacing relay: After replacing relay:
takair Posted March 5 Report Posted March 5 I would clip in a recording meter like a Fluke to see if the spikes are on the bus or the engine analyzer. You can set it to beep at the highs and lows to see if there is any trend. If it makes you feel better perhaps it is simply a desulfating feature that you didn’t know you had. People pay extra for that in a trickle charger.
Flyler Posted March 5 Author Report Posted March 5 10 minutes ago, takair said: I would clip in a recording meter like a Fluke to see if the spikes are on the bus or the engine analyzer. You can set it to beep at the highs and lows to see if there is any trend. If it makes you feel better perhaps it is simply a desulfating feature that you didn’t know you had. People pay extra for that in a trickle charger. I was thinking about that, but don't think I have a fancy enough meter. It would actually be rather easy since I have that handy Battery Minder plug in the luggage compartment that goes straight to battery voltage. More importantly, I left this jibberish in my original post, specifically so I could show it to you after you answered my question anyways, without me bothering you via text message. "Rob Takacs Time to Answer Question Anyways." I posted at 7:36, so in less than an hour you managed to answer my question anyways. Best A&P ever? I think so.
takair Posted March 5 Report Posted March 5 I have the meter, you have the plane. Swing by and see the new hangar and take me for a ride. 1
takair Posted March 5 Report Posted March 5 lol. I just reread your post. I thought it was a biblical reference. lol.
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