no power to overhead lights 1980 M20K

[N231SM]

If you do not have a wiring knack  please delete this.

Is there a switch I am missing to activate the overheads? As I recall. They are -should be-constant hot.

 

Where is the fuse?

 

Serial # is 25-0317. 

The hot that goes to the front overheads is not longer hot. It was before I r/r interior. That stinks, but it is what it is. 

Wiring diagram - block 16 -shows the hot to the front overhead lights JK-LC 06A20 is supposed to bring in the power. It is coming from a dual pos at the “clock panel” via JK-LC-5A20.  The other pos at the clock is JK-DV09A20,  a hot coming - from- I do no know where. Anyone have a diagram for that?

I am getting dizzy here. I have a Davatron clock. I assume that is not original. The power to the clock is unknown but the wiring is a lot smaller. So I assume that was changed and has a different hot. 

I suppose the thing to do disconnect the LC06A20 and run new power. It terminates there at the overhead light circuit and does not appear to continue anywhere else. I can put in a fuse and call it a day.

Any ideas? Help/ 

[Piloto]

Look for an In-line fuse in the tail cone next to the big access panel, by the battery relay.

José

[carusoam]

Also... Check the other things that are constantly hot to see if there is a reason for the fuse challenge...

My O keeps the lighter plug and a few other lights hot all the time.

your POH May have a wiring diagram, but that is a lot of detail to make it to the POH... the MM would definitely have it...

Best regards,

-a-

[milotron]

Well, when I left these on and killed my battery, I discovered that these lights are 'supposed' to be wired after the 'fuel flow memory' switch on the right side of the panel. That switch, according to the wiring diagram, will isolate the overhead lights, the factory fuel flow meter and the factory clock.

 

That was 40 or more years ago. Your current wiring reality may be very different....

 

iain

[jaylw314]

2 hours ago, N231SM said:

If you do not have a wiring knack  please delete this.

Is there a switch I am missing to activate the overheads? As I recall. They are -should be-constant hot.

 

Where is the fuse?

 

Serial # is 25-0317. 

The hot that goes to the front overheads is not longer hot. It was before I r/r interior. That stinks, but it is what it is. 

Wiring diagram - block 16 -shows the hot to the front overhead lights JK-LC 06A20 is supposed to bring in the power. It is coming from a dual pos at the “clock panel” via JK-LC-5A20.  The other pos at the clock is JK-DV09A20,  a hot coming - from- I do no know where. Anyone have a diagram for that?

I am getting dizzy here. I have a Davatron clock. I assume that is not original. The power to the clock is unknown but the wiring is a lot smaller. So I assume that was changed and has a different hot. 

I suppose the thing to do disconnect the LC06A20 and run new power. It terminates there at the overhead light circuit and does not appear to continue anywhere else. I can put in a fuse and call it a day.

Any ideas? Help/ 

AFAIK, most Davtron clocks have an internal AA battery.  Obviously, those would not require an "always on" circuit, which apparently allowed the previous owner of my J to cut the wire to that circuit at the battery.  I only have half of a fuseholder there.

[lotsofgadgets]

My overheads quit working after my panel upgrade ('82 J) the problem turned out to be the disconnect plug in the tailcone.  One of the pins wasn't making contact.  Took the plug apart and reseated the pin.  Works good now.

[N231BN]

If you look at the bottom of the applicable schematic you will see the master relay next to the battery. Wire 21LC01B18 comes off the relay and goes to a 5A fuse. That is most likely your culprit. As José said, it is physically located near the relay and battery box.

 

[carusoam]

13 hours ago, N231SM said:

If you do not have a wiring knack  please delete this.

 

[carusoam]

Try as much as you can....

Having the knack or not... That can’t be deleted.  

I bet a dozen people have learned about the fuse in the tail next to the relay...

The awesome power of MS... Get the knack!  (Strange 80’s music reference)

Best regards,

-a-

[N231SM]

What an incredible resource.!!  Thanks guys. That has to be the problem. Will get on it today if work allows. 

 

 

 

 

 

 

[carusoam]

2 minutes ago, N231SM said:

What an incredible resource.!!  Thanks guys. That has to be the problem. Will get on it today if work allows. 

 

 

 

 

 

 

See if you can post a pic of the fuse when you get back there?

Best regards,

-a-

[N231SM]

It was a 5 amp with a strange  pink? internal swirl on one end. I pitched it but will look thru trash. 

[testwest]

Was that fuse the issue? Can't leave us hanging!

(and I need to Get the Knack on itunes soon)

[Yetti]

On 4/25/2018 at 5:00 PM, N231SM said:

It was a 5 amp with a strange  pink? internal swirl on one end. I pitched it but will look thru trash. 

generally those are the slow blow type fuses

[Pritch]

Following with interest, my Mistress just came out the Avionics shop after an upgrade and I just noticed today my overhead lights and clock are not working.  Will investigate the 5 amp fuse tomorrow.

Pritch