rv969wf
Well Known Member
I've been having a problem with my NipponDenso alternator which I cannot figure out. It all started at around the 350 hour mark since new. Here's what is going on: In day VFR, normally I'm showing 13.5 - 13.8 volts and it's charging around 8 amps. After flying for 30 minutes or so, the voltage falls to 12.4-12.5 with zero amps, NOT charging, then after about 30 minutes it will start trickling up to 1-2 amps with voltage upwards to 12.8 then after a few more minutes I'm up to 13.8 volts and charging 14 amp. After the battery is charged, the amps fall back to around 8. Then here we go again after flying for another 30 minutes, same thing happens over and over. This has been going on for a long time. First I made sure I had good grounds, even ran a ground strap from Alt body to the case, no paint hindering good ground, bare metal ok. I've taken all connections loose to make sure there is no corrosion and sanded all contact points. I even replaced the voltage regulator at around 360 hours. Everything seemed ok for about a 100 more hours till I flew to Oshkosh and the same thing happened over and over and over. The alt now has 510 hour TT. When I take the alt and put it on a test machine, nothing is found even after spinning it for an hour. Can anyone tell me what is going on other than replacing the whole unit with a new one. Any comment would be appreciated.
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