KR>Re: electric fuel pumps / failures

2021-12-01 Thread John Gotschall
On Wed, Dec 1, 2021, 13:32 Randy Smith via KRnet wrote: On your 172 unless someone wired it wrong the 1 wire coming off the solinoid is a ground wire. When the master is turned off everything but the clock (unless it is a wind up) is off.

KR>Re: electric fuel pumps / failures

2021-12-01 Thread Randy Smith via KRnet
On your 172 unless someone wired it wrong the 1 wire coming off the solinoid is a ground wire. When the master is turned off everything but the clock (unless it is a wind up) is off.  On Wednesday, December 1, 2021, 07:52:33 AM CST, Flesner wrote: On 11/30/2021 8:19 PM, Mark Langford

KR>Re: electric fuel pumps / failures

2021-12-01 Thread Flesner
On 11/30/2021 8:19 PM, Mark Langford wrote: Nothing wrong with two switches, other than stuff like accidentally turning them both off at the same time, or your fuel pressure increasing dramatically because you have two pumps running in series (and causing some other problem). +++

KR>Re: electric fuel pumps / failures

2021-11-30 Thread Mark Langford
I had a failure of one side of the DPDT switch (double pole, double throw), and that story is at the bottom of the link y'all are referring to, http://www.n56ml.com/electrical/index.html . I've learned that lesson, and my answer is "use super high quality parts for critical items", hence the H

KR>Re: electric fuel pumps / failures

2021-11-30 Thread John Gotschall
Larry wrote: " I've seen DT/ center off switches, both SP and DP fail in one "throw" cause both "throws" to fail or become inop. " I agree. I have seen those fails also. If you put two or more functions on one switch, be prepared to loose all the functions upon failure of the switch. You

KR>Re: electric fuel pumps / failures

2021-11-30 Thread Flesner
On 11/30/2021 12:13 PM, Michael wrote: I have been reading Mark's electrical blog and did a bit of re-drawing purely for my own use and logbook but have attached if you find value in it. ++ I can't seem to open your attached fil

KR>Re: electric fuel pumps / failures

2021-11-30 Thread Flesner
On 11/30/2021 2:29 PM, John Gotschall wrote: In my Cessna 172 the master solenoid isolated everything. Really, everything. Including the starter solenoid. The only thing not isolated by the master solenoid was one lonely fuse feeding the master switch contact that fed only the master solenoid

KR>Re: electric fuel pumps / failures

2021-11-30 Thread John Gotschall
In my Cessna 172 the master solenoid isolated everything. Really, everything. Including the starter solenoid. The only thing not isolated by the master solenoid was one lonely fuse feeding the master switch contact that fed only the master solenoid coil. That way when the master was off, there