Where is the in-line fuse ??

[FLYINGBROMAN]

1982 Mooney 231:  After some recent additional glass panel upgrades, the "MEMORY" switch for my FT 101 Hoskins fuel flowmeter no longer works.  In flight flow and push for total trip consumption continues to work great.  Once, the power is off, no more memory.  It is my understanding that the tiny memory switch actually applies continuous 12 V to the FT 101 thereby charging a very small memory battery between flights with minimal current requirements.  It is possible that tiny wire was "grounded" somehow during the complex avionics upgrades.  The Hoskins FT 101 must be fused somewhere along a path back to the battery - but where?   Does anyone know where this fuse is located. 

An original wiring diagram would likely show the location (panel, tail etc) but mine was lost during Hurricane Katrina.  A review of posts here suggests that original copies of these folded schematics is hard to come by.  Thanks for any help !

[N201MKTurbo]

The fuses were originally back by the master relay in the tail. It is the only place that has power with the master off. The only place safe to fuse it is near its source.

[RoundTwo]

12 hours ago, FLYINGBROMAN said:

1982 Mooney 231:  After some recent additional glass panel upgrades, the "MEMORY" switch for my FT 101 Hoskins fuel flowmeter no longer works.  In flight flow and push for total trip consumption continues to work great.  Once, the power is off, no more memory.  It is my understanding that the tiny memory switch actually applies continuous 12 V to the FT 101 thereby charging a very small memory battery between flights with minimal current requirements.  It is possible that tiny wire was "grounded" somehow during the complex avionics upgrades.  The Hoskins FT 101 must be fused somewhere along a path back to the battery - but where?   Does anyone know where this fuse is located. 

An original wiring diagram would likely show the location (panel, tail etc) but mine was lost during Hurricane Katrina.  A review of posts here suggests that original copies of these folded schematics is hard to come by.  Thanks for any help !

Do your overhead lights work? If so, the fuse is OK.
 

Here’s a snip of my wiring diagram showing the fuse. The fuse is down near the bottom, towards the left. Mine is an 88 J, but all of my wiring is prefixed with JK- so I’m assuming it is a common harness.

The fuse for the clock and overhead lights is a black in-line fuse about 6” from the master relay on the side of the battery box.

[skykrawler]

In the diagram above, that fuse is for the clock and located in the back by the battery.

There may be an inline fuse in the area behind the master switch.  Is it possible that the switch was inverted during the panel rebuild and you are actually disabling the memory?

[FLYINGBROMAN]

Thanks to everyone - WOW - I never thought about the overhead lights - great tip - indeed those LIGHTS and my CLOCK are dead in addition to no memory power to the FT 101.

With all that good news, I still cannot find the fuse in the tail cone.  There is a lot of stuff packed in there.  Does RoundTwo's schematic show the fuse in the tailcone?

[N201MKTurbo]

Maybe when they did your avionics, they removed it accidentally. Which is why you cannot find it.

[LANCECASPER]

33 minutes ago, FLYINGBROMAN said:

Does RoundTwo's schematic show the fuse in the tailcone?

Yes - look at the bottom of the schematic to the left of the middle.

[1980Mooney]

3 hours ago, FLYINGBROMAN said:

Thanks to everyone - WOW - I never thought about the overhead lights - great tip - indeed those LIGHTS and my CLOCK are dead in addition to no memory power to the FT 101.

With all that good news, I still cannot find the fuse in the tail cone.  There is a lot of stuff packed in there.  Does RoundTwo's schematic show the fuse in the tailcone?

As @RoundTwo said “The fuse for the clock and overhead lights is a black in-line fuse about 6” from the master relay on the side of the battery box.”

It originally was a black twist type inline fuse holder with a cylindrical glass fuse. 

[FLYINGBROMAN]

I think I found it, off one limb of the master relay!  Actually I found it in my own photos taken during replacement of the original 40 year old master solenoid a few years ago.  Explains why I could not "see" it in the airplane today, because it is covered up by cable attachments to the new solenoid.

Going take a harder look tomorrow.

Thanks again for all the great help.

 

[Tim-37419]

What a find!