master/power stuck on

[Yetti]

31 minutes ago, eman1200 said:

for the record, are there people who have replaced the oem master with the Lamar sts-m12?  from the specs:

"Silver Contacts provide 300A in-rush & 150A continuous-duty capability Much higher than OE units

which is higher in-rush but fewer continuous.  I think other than starting the plane this should be more than enough but just wanted to check.

technically the one you have is rebuildable.  Maybe.     Taking the fuse out kind of means it is still working.   You have another wire somewhere that was providing 12 volts to the master.  It could have been as simple as water from the com panel falling on the master switch.  I would spend some time with a test light/VOM before I replaced the solenoid.

I would be replacing the master switch prior to the Master Relay.

What the heck is that third relay for?  That is not stock.     

[eman1200]

5 minutes ago, Yetti said:

technically the one you have is rebuildable.  Maybe.     Taking the fuse out kind of means it is still working.   You have another wire somewhere that was providing 12 volts to the master.  It could have been as simple as water from the com panel falling on the master switch.  I would spend some time with a test light/VOM before I replaced the solenoid.

I would be replacing the master switch prior to the Master Relay.

What the heck is that third relay for?  That is not stock.     

we did plenty of multimeter zapping and right now everything is pointing to the relay.  the switch seemed to be ok, although I don't think it would be a bad idea to replace it. the oem part has 4 posts as well. this is the 'new' one, which kind of lines up with how the existing one is wired.  sort of:

 

[Yetti]

8 minutes ago, eman1200 said:

we did plenty of multimeter zapping and right now everything is pointing to the relay.  the switch seemed to be ok, although I don't think it would be a bad idea to replace it. the oem part has 4 posts as well. this is the 'new' one, which kind of lines up with how the existing one is wired.  sort of:

 

this would be the more accurate one      https://peerlesselectronics.com/6041h105-relay?gad_source=1&gad_campaignid=20663341848&gclid=CjwKCAjwlaTGBhANEiwAoRgXBbhuWKo-Lr1UUFUmSylE4m2OjCHjmOhe2gzIn47Nnb8yoD3thidkdxoCuMEQAvD_BwE

sky geek is a little less dollars.   https://skygeek.com/eaton-aerospace-6041h105-relay-12v-1-15-electromagnetic.html?gad_source=1&gad_campaignid=13706325759&gclid=CjwKCAjwlaTGBhANEiwAoRgXBRz5hEL80QIv2peWx0foyLVmYs_eV-jhmk7bUAO7C4QKbzg-2ih1shoCJYwQAvD_BwE

 

[Yetti]

started as cutler hammer bought by Eaton.

 

At one point I found it at McMaster Carr for $200.00

[eman1200]

20 minutes ago, Yetti said:

this would be the more accurate one      https://peerlesselectronics.com/6041h105-relay?gad_source=1&gad_campaignid=20663341848&gclid=CjwKCAjwlaTGBhANEiwAoRgXBbhuWKo-Lr1UUFUmSylE4m2OjCHjmOhe2gzIn47Nnb8yoD3thidkdxoCuMEQAvD_BwE

sky geek is a little less dollars.   https://skygeek.com/eaton-aerospace-6041h105-relay-12v-1-15-electromagnetic.html?gad_source=1&gad_campaignid=13706325759&gclid=CjwKCAjwlaTGBhANEiwAoRgXBRz5hEL80QIv2peWx0foyLVmYs_eV-jhmk7bUAO7C4QKbzg-2ih1shoCJYwQAvD_BwE

 

I'm curious why you recommend those two, I see no specs on those links.  so while yes, they 'look' the same, without specs how can you compare?  I know other people have probably already done that, but other than mounting brackets, if the specs are the same but one is 1/4 the price......  it would be nice not to have to remount it but that's not worth the extra price to me.  BUT, if that's simply the better choice, then that's what I'd go with.  the one I listed is listed as the pma replacement for the cutler hammer according to lamar.

[RangerM20]

A '64 C model I worked on several years ago had this same problem.  Turned out to be the master switch itself.

[Justin Schmidt]

While people that don't know call everything a solenoid.  In reality a solenoid uses electrical force into physical motion.  Starter (what ingages with ring gear) is a solenoid. 

[Yetti]

3 hours ago, eman1200 said:

I'm curious why you recommend those two, I see no specs on those links.  so while yes, they 'look' the same, without specs how can you compare?  I know other people have probably already done that, but other than mounting brackets, if the specs are the same but one is 1/4 the price......  it would be nice not to have to remount it but that's not worth the extra price to me.  BUT, if that's simply the better choice, then that's what I'd go with.  the one I listed is listed as the pma replacement for the cutler hammer according to lamar.

What is the AP/IA comfortable signing off on is the best answer.           We used to run high amperage solenoids to switch the power to high amperage radios.    The metal cans would fail at a higher rate than the black plastic ones.     

[skykrawler]

The solenoid in the master relay could be internally shorted to ground.

I would remove the wire from the master relay that provides the ground path that energizes the relay (re: to master switch).   If the relay opens it implies there is a a ground being applied through that wire from something other than the master switch.   If it stays energized, it's probably an internal short to ground.

 

 

[eman1200]

The solenoid in the master relay could be internally shorted to ground.
I would remove the wire from the master relay that provides the ground path that energizes the relay (re: to master switch).   If the relay opens it implies there is a a ground being applied through that wire from something other than the master switch.   If it stays energized, it's probably an internal short to ground.
 
 

I’ll try this, ty.

[eman1200]

Put the brand new relay in, same behavior. What we found was with the master power off but still getting power to the panel, pulling the FLAP cb killed the power. With no power going to the panel, inline fuse in, flap cb out, we can still lower the flaps. That is bizarre. Does anyone else have this inline fuse on the master relay?

[47U]

25 minutes ago, eman1200 said:

Does anyone else have this inline fuse on the master relay?

Do you have a SureFly mag?  They require a hot lead per the installation documents, often taken from the master relay..

[Z W]

I have a similar inline fuse. In my plane, it connects directly to the main power line coming off the battery at the master relay, so it is always hot, and runs forward into the cabin. It therefore provides always-hot power to something in the cabin, though I never figured out exactly what, or if it's even still connected to anything. I would expect it to be something like a clock or cabin light that you would want powered with the master off.

For what you describe, I am still suspicious of the mystery 3rd not-stock relay mounted to the aft of your battery without any terminal covers. Someone has done something non-standard with your wiring. Does that relay send any power thorough wires forward into the cockpit?

[eman1200]

I have a similar inline fuse. In my plane, it connects directly to the main power line coming off the battery at the master relay, so it is always hot, and runs forward into the cabin. It therefore provides always-hot power to something in the cabin, though I never figured out exactly what, or if it's even still connected to anything. I would expect it to be something like a clock or cabin light that you would want powered with the master off.
For what you describe, I am still suspicious of the mystery 3rd not-stock relay mounted to the aft of your battery without any terminal covers. Someone has done something non-standard with your wiring. Does that relay send any power thorough wires forward into the cockpit?

Just a relay for the avionics master. It’s connected to a three way switch in the panel, UP only works when the master is on, middle is off and down powers the avionics even with the master off.

[Z W]

3 minutes ago, eman1200 said:

Just a relay for the avionics master. It’s connected to a three way switch in the panel, UP only works when the master is on, middle is off and down powers the avionics even with the master off.

Sounds like if your 3-way avionics master switch were to fail or have an internal short, it could be back-feeding power into your master relay or your panel, depending on how they wired it. You know something is back feeding power, and it would have to be either the fused line you sent a picture of, or your non-stock avionics master relay.

[eman1200]

Sounds like if your 3-way avionics master switch were to fail or have an internal short, it could be back-feeding power into your master relay or your panel, depending on how they wired it. You know something is back feeding power, and it would have to be either the fused line you sent a picture of, or your non-stock avionics master relay.

Yup, leaning heavily towards that in line fuse. Thank you!

[Z W]

If it were my plane, I would want that extra relay and 3-way avionics master switch removed and everything returned to stock configuration. There are reasons and failure mode considerations it's done the way it is, and what you are experiencing may be one of the reasons the factory didn't include the option to turn on the avionics with the master off in the first place.

[eman1200]

If it were my plane, I would want that extra relay and 3-way avionics master switch removed and everything returned to stock configuration. There are reasons and failure mode considerations it's done the way it is, and what you are experiencing may be one of the reasons the factory didn't include the option to turn on the avionics with the master off in the first place.

I would prefer leaving as is and just learning more about how everything works. It’s been flawless with this one exception.

[Z W]

In factory configuration, the avionics master is "on" by default meaning if its relay fails, the avionics stay on and won't turn off until the master goes off. When you flip the avionics master switch to off, the relay triggers and severs the connection to the avionics bus. You know the relay has failed when you try to power off the panel but it stays on until you turn the master off.

If your avionics master relay in the tail fails, do your radios, flaps, lights, and gear continue to work? Or does your entire panel go dark? Where would you look to find the answer to the question, if you don't know?

[Justin Schmidt]

That inline fuse is for dome light and panel clock. Clearly on the schematic. 

[Mmrkulic]

1 hour ago, Justin Schmidt said:

That inline fuse is for dome light and panel clock. Clearly on the schematic. 

Exactly now the mystery how and why its back feeding the buss providing power to half the panel . Especially with master off hes able to run the flaps up and down as soon as we unplug the dome/clock fuse plane is normal. Its no trigger the relay its literally back feeding via that 18guage wire so bizzare.

[MikeOH]

6 hours ago, eman1200 said:

With no power going to the panel, inline fuse in, flap cb out, we can still lower the flaps.

If I'm reading this right, you say you can run the flaps with the flap CB pulled???!?!??

Something is seriously wrong if that is the case.  I can't quite form a mental schematic of how your NON-STANDARD avionics switch could play into this, but it sounds like you are backfeeding both the master relay and the flaps!

5 hours ago, eman1200 said:

It’s been flawless with this one exception

Uh, maybe TWO exceptions!  And, both are pretty BIG FLAWS, IMHO! Despite your 'preference' for leaving the avionics switch in place, you might consider at least temporarily disconnecting it and seeing if these two 'flaws' go away.

[N201MKTurbo]

Look at your aux bus jumper at the top of your CB panel. When that thing breaks, all kind of weird stuff happens.

[skykrawler]

4 hours ago, N201MKTurbo said:

Look at your aux bus jumper at the top of your CB panel. When that thing breaks, all kind of weird stuff happens.

The AUX and Avionics bus gets power from the Battery Bus which gets power from the Master (Battery) Relay.

Do you have a problem with mice?

[N201MKTurbo]

So does the flaps….