---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 08/16/21: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:22 PM - Blowing fuses on B&C BC433 alternator (Sam Hoskins) ________________________________ Message 1 _____________________________________ Time: 12:22:12 PM PST US From: Sam Hoskins Subject: AeroElectric-List: Blowing fuses on B&C BC433 alternator Hello all. I haven't been on this list for some time, but now could use a bit of advice. I have a Quickie Q-200 , sporting a hopped up O-200. Pistons, RWS electronic fuel injection and electronic ignition. It takes around 15 amps to stay in the air, between the fuel injectors, spark plug coil and fuel pumps, it requires a lot of juice. All this was wired up while attempting to follow Bob's best practices. The B&C 433 alternator has three legs for output and they go to their proprietary voltage regulator. Each leg has a 20 amp in-line fuse before connecting to the regulator. Here is the BC433 wiring diagram . About 50 flight hours ago, one of the fuses blew. Really blew, it partially melted the plastic coating. I couldn't really find anything wrong, but I thought possibly there was a short from one of the butt connectors to the firewall, nothing definitive though. Last week, 50 flight hours later, another fuse blew. I don't know if it was on the same leg as I didn't record it the first time it happened. All the wiring from the alternator to the VR seems to be 100%. I put my VOM on the leads and they all checked out per the B&C service manual. https://bandc.com/wp-content/uploads/2018/05/pmr3a-trouble.pdf I called B&C and talked to TJ. We went over what I had done, but he didn't really have a solid suggestion, other than pulling the engine (big bad job) and pulling the alternator off and sending it in. He did suggest that I put a meter on the leg that blew the fuse and rotate the prop, but it showed nothing. After I put everything together I ran the engine and everything seemed to be fine. I thought I'd run it by the brain trust and see if there were any other root cause suggestions. Thanks. Sam ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.