• PiperForum.com is a vibrant community of Piper owners and pilots. Our over 1,500+ active members use Piper Forum to swap technical knowledge, plan meetups and sell planes/parts. We host technical knowledge of general aviation topics and specific topics on J3-Cubs, Cherokees, Comanches, Pacers and more. In addition to an instant community of pilots for you, PiperForum.com is a library of technical topics, airplane builds, images, technical manuals, technical documents and more.

    Access to PiperForum.com is subscription based. Subscriptions are only $49.99/year or $6.99/month to gain access to this great community and unmatched library of Piper knowledge.

    Click Here to Become a Subscribing Member and Access PiperForum.com in Full!

My electrical system seems weird

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

skywag

BE300 CE500 DA-50 LR-JET
Joined
Jun 23, 2012
Messages
2,593
Reaction score
941
I've been monitoring my electrical system. My 1967 PA-28-180C has an Electronics International digital volt amp meter.

VA-1A.jpg


it is on a circuit breaker that also has a Davtron OAT meter

301C-led.jpg


and a Davtron M811 clock.

811-gry-300dpi.jpg


Before engine start and with ALL the other circuit breakers pulled, these three digital instruments pull 3.1 amps. (seems high to me) Is that possible?

When the pitot heat breaker is set and the heat turned on the amps go to about 11 amps. That seems normal to me.

But it all changes when the engine is started and power is being provided by the alternator. With all the CBs set and every switch is off, I still see 3.1 amps. But when the pitot heat is turned on the AMP meter goes DOWN!! to about 0 (zero)

Something seems wrong about that. Shouldn't it go up to 11, just as it was with battery only? There is no smoke!!
 
Last edited:

Latest posts

Back
Top