Wildly erratic amp reading

[FlyingBanker]

I've got an RV-6A with an O-360-A1A engine and a PlanePower alternator. I've got a G3X PFD with Garmin engine monitoring. My normal amp reading is in the 21-40 range depending on what I have turned on. Today on a flight, everything started normally, but almost immediately after liftoff, the amp readings began fluctuating wildly, including as high as 787. It continued I tried turning off different devices to no avail. I turned back to airport and on downwind, the amp reading settled back down to normal stable reading and stayed there until touchdown when it started fluctuating wildly again. I'm more ignorant that I probably need to be on electrical systems. Any ideas on what I should be looking for to diagnose and address this? I appreciate any help from this very knowledgeable group.

 

[mburch]

Assuming you have an ammeter shunt and not a Hall effect current sensor... this type of behavior is almost always due to a lose or intermittent connection between the shunt and the GEA 24, usually right at the shunt itself. I'd start there - remember, tiny increases in resistance will show up as large increases in sensed current.

 

[D-Dubya]

I concur, it sounds like a loose connection. If you can't find a loose screw or other connection, then check the fuses going to the shunts. If memory serves me correctly, there should be a 1 amp fuse on each of the legs coming off the shunt going to your EFIS. You may need to pull them out and re-seat them. They're typically in a harsh environment and may be prone to getting a little crud on the connections.

 

[FlyingBanker]

Yep, loose connection at the shunt. Thanks!