Need your help/ideas on what to prioritize to root cause my issue; alternator itself, voltage regulator, or wiring?
So I pulled my tail off of my RV4 to add doublers that were necessary on horizontal and vert stab. Plane hasn't flown since mid or early February. I had to crawl around in the tailcone which I figured could have knocked some wires loose but nothing found. I also added a bracket between alternator and an empty starter bolt. Otherwise I didn't touch the charging system while I was down for maintenance.
I planned to test fly last Friday but when I fired it up and went through checks, I was showing a draw and 11.5 volts or so, not 14.5 to 14.7 like usual so I pulled the cowl to test field and battery connection on alternator and any loose wires in tailcone. Everything tested fine but I noticed the ground wire coming off the shielded field wire and the alternator ground (both at alternator end) looked like they could have a break in the wire due to prior owner performing a weak splice. Well I decided I'd run the plane at least to see if it was charging and low and behold it was. I didn't fly it but ground ran it for 5 to 10 minutes charging the whole time even after flipping off my alternator switch and master and flipping back on.
I cut ground and power (for field only) back and spliced on new wires and better protected them. I plugged it all in and fired it up last night and no charge! Ran same test procedure of field and 12v at alternator back to battery. Now this time I wasn't confident I was getting power to the positive field wire. I would see 12v but then id move around and seemed to read 0 then move more and get 12v. Not sure if my multimeter probes weren't getting into the plug or if I had a wiring issue. So decided to chase the field wire back. Went to voltage regulator and it seemed to have 12v when my master was switched on. Tested my alternator switch because it also seemed like it could be a culprit but it tested fine. Go back out to field wire at the alternator and it tested fine.
Fired up and the thing is charging again (like after my testing on Friday). Flipped alternator and master and did numerous restarts and it was showing 14.5v on one EFIS and 14.3 on the other (not sure why they differed and I didn't notice if they differed before or not).
So should I be pulling the denso 14184 alternator that has fewer than 30 hours on it? Or should I be checking voltage regulator and wiring to see if there is a break somewhere else? How do I test voltage regulator and wiring for this intermittent issue?
So I pulled my tail off of my RV4 to add doublers that were necessary on horizontal and vert stab. Plane hasn't flown since mid or early February. I had to crawl around in the tailcone which I figured could have knocked some wires loose but nothing found. I also added a bracket between alternator and an empty starter bolt. Otherwise I didn't touch the charging system while I was down for maintenance.
I planned to test fly last Friday but when I fired it up and went through checks, I was showing a draw and 11.5 volts or so, not 14.5 to 14.7 like usual so I pulled the cowl to test field and battery connection on alternator and any loose wires in tailcone. Everything tested fine but I noticed the ground wire coming off the shielded field wire and the alternator ground (both at alternator end) looked like they could have a break in the wire due to prior owner performing a weak splice. Well I decided I'd run the plane at least to see if it was charging and low and behold it was. I didn't fly it but ground ran it for 5 to 10 minutes charging the whole time even after flipping off my alternator switch and master and flipping back on.
I cut ground and power (for field only) back and spliced on new wires and better protected them. I plugged it all in and fired it up last night and no charge! Ran same test procedure of field and 12v at alternator back to battery. Now this time I wasn't confident I was getting power to the positive field wire. I would see 12v but then id move around and seemed to read 0 then move more and get 12v. Not sure if my multimeter probes weren't getting into the plug or if I had a wiring issue. So decided to chase the field wire back. Went to voltage regulator and it seemed to have 12v when my master was switched on. Tested my alternator switch because it also seemed like it could be a culprit but it tested fine. Go back out to field wire at the alternator and it tested fine.
Fired up and the thing is charging again (like after my testing on Friday). Flipped alternator and master and did numerous restarts and it was showing 14.5v on one EFIS and 14.3 on the other (not sure why they differed and I didn't notice if they differed before or not).
So should I be pulling the denso 14184 alternator that has fewer than 30 hours on it? Or should I be checking voltage regulator and wiring to see if there is a break somewhere else? How do I test voltage regulator and wiring for this intermittent issue?