Problem with fluctuating Amperage

dtaylor · #1 10-24-2011, 10:02 PM

Any ideas about what would cause my amperage to start fluctuating wildly about 5 minutes into a flight?

It starts out fine after takeoff at 15 amps and then goes to -50 amps for 30 seconds, and then gyrates between 5 amps and -50 amps for a minute and then goes back to normal. It repeats this sequence every 5 minutes.

My fuel gages also go down to zero during this episode and then back to normal.

Is my B&C LR3C Linear Regulator going bad?

(I'm getting these readings from my Grand Rapids EIS engine monitor. It's hooked up to a Grand Rapids EFIS Sport.)

Thanks for the help!

David T.
cincinnati

Walt · #2 10-25-2011, 06:24 AM

What is the Voltage doing? Neg 50 amp seems awful high unless you got everything (all lights/strobes/seat heaters/?) on and even then that seems high for an RV.

jdeas · #3 10-25-2011, 07:22 AM

The hint to me would be the fuel gauge changes. If you have a resistive type it is a 'single ended' sensor and depends on a good gnd connection to the EFIS for a correct reading.
I would check the EFIS gnd connections and maybe throw a second meter on the current shunt to see if those readings are real.