Maule’s electric wiring gotchas.

Discussion on keeping your aircraft airworthy and legal and/or any technical topics.


Post Reply
Cash
Posts: 47
Joined: Mon Dec 17, 2012 9:02 pm
Location: Mcalester
Contact:

Maule’s electric wiring gotchas.

Post by Cash »

My M7 235B has a wiring problem done at factory. The mag/starter switch bat side comes from a breaker that also feeds the done light, panel dimmer, and stall light. Guess what happens if you get a short or what ever in one of these unnecessary for flight items like the dome light that pops the breaker? You can not start the airplane! Has anyone rewired the mag/starter switch with a single wire through its own breaker? My IA is ok in doing that and can’t believe Maule wired it this way. Les
Flyrider

asa
100+ Posts
Posts: 296
Joined: Sat Dec 22, 2018 1:09 pm
Location: KY+AK
Contact:

Re: Maule’s electric wiring gotchas.

Post by asa »

Clearly you are only trying to start the engine to taxi it to a maintenance facility to fix the short circuit.... right? Seems less like a problem and more like Maule built in a checks and balances system to ensure you're following 91.213. They're super thoughtful with things like that :wink: :lol:

Cash
Posts: 47
Joined: Mon Dec 17, 2012 9:02 pm
Location: Mcalester
Contact:

Re: Maule’s electric wiring gotchas.

Post by Cash »

Clearly you realize not all Airplanes are always on an airport with a A&P.
Flyrider

User avatar
Andy Young
100+ Posts
Posts: 1545
Joined: Wed Oct 05, 2011 7:10 am
Location: Alaska, Antarctica, Colorado, and Others
Contact:

Re: Maule’s electric wiring gotchas.

Post by Andy Young »

Clearly not everyone recognizes attempts at humorous light sarcasm. ;-)

Cash
Posts: 47
Joined: Mon Dec 17, 2012 9:02 pm
Location: Mcalester
Contact:

Re: Maule’s electric wiring gotchas.

Post by Cash »

Sorry ASA and Andy that I missed the humor in the post. However when this problem showed its ugly face to me, I was at a remote private strip without an amp meter nor electric wire to jump the mag/start switch must less the electric schematics that showed the possible problem. Was it a bad battery that was fully charged yet now only enough power to bring up the gages etc or was it the starter solenoid or starter? A major problem that was anything but funny. In hind site it it could be considered funny how Maule wired the Mag/starter switch. My Cessna has a dedicated circuit to switch. Again sorry. I must be still upset about the problem it caused me and when I think about the places a Maule is used by most this could be a major problem to others.
Flyrider

User avatar
Andy Young
100+ Posts
Posts: 1545
Joined: Wed Oct 05, 2011 7:10 am
Location: Alaska, Antarctica, Colorado, and Others
Contact:

Re: Maule’s electric wiring gotchas.

Post by Andy Young »

No worries on my part. I’ve occasionally misread the humorous intent in a comment.

You bring up an interesting potential liability that I do want to dig into, next time I get a chance to look at the wiring diagram.

asa
100+ Posts
Posts: 296
Joined: Sat Dec 22, 2018 1:09 pm
Location: KY+AK
Contact:

Re: Maule’s electric wiring gotchas.

Post by asa »

While I was choosing my CB's and wire sizes for my rebuild, I noticed this in the wiring diagram. It's odd but I'm assuming Maule just treated it as a "miscellaneous" circuit breaker without much thought into that failure mode. They do some funny combinations in others as well, but without the potential ramifications.

Things like this make me think it could be beneficial to carry a PDF of the wiring diagram on my ipad or phone.

Cash
Posts: 47
Joined: Mon Dec 17, 2012 9:02 pm
Location: Mcalester
Contact:

Re: Maule’s electric wiring gotchas.

Post by Cash »

That’s what I did ASA for quick reference from where ever. My M7 now has a dedicated wire and breaker from bus bar to start/mag switch. In my case some way the wire to stall light got loose and popped breaker eliminating the possibility of starting the plane. However it could have been the dome light or pesky dimmer switch having the same effect. I just wonder how many Maule models have the same wiring.
Flyrider

Post Reply

Who is online

Users browsing this forum: No registered users and 13 guests