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CB Rocker Switches

Posted: Thu Feb 20, 2020 9:45 am
by jdsmaule
It's annual time on my friends MX-7-235, his fuel boost pump rocker switch is getting difficult to operate. I understand these are discontinued and newer Maule's are using toggle switches. Does anyone have a source for these switches? New or used? Part number is 20TC-BA-5.

Thanks!

Posted: Thu Feb 20, 2020 1:16 pm
by rv8bldr
This just happened to me on my M5-235C. The switch completely bit the dust.

I called Maule and I think it was Brent who got on the phone and said "I haven't seen one of those in 30 years. They don't make them any more and we don't have any in stock"

Oops. I tried looking everywhere but no luck

I bought a 10A break toggle switch from Aircraft Spruce, made a little mounting plate to go where the rocker breaker was before and just installed it. This was at the suggestion of my A&P (called AME here in Canada).

Here is the link on the Aircraft Spruce Canada website:

https://www.aircraftspruce.ca/catalog/e ... tbrkr2.php

Hope this helps

Posted: Thu Feb 20, 2020 1:44 pm
by Andy Young
I have sourced used switches from a low-wing Piper of some sort when I needed one. It wasn’t identical, but it was very similar, and fit perfectly. Amp rating etc was correct.

Posted: Thu Feb 20, 2020 2:30 pm
by Craigh-KRPH
Searching "piper rocker switch" on eBay yielded a few results that might work for you.

Texas Air Salvage might also be another parts source: https://www.texasairsalvage.com/main_vi ... id1=212959

Posted: Fri Feb 21, 2020 7:24 am
by rv8bldr
Well, poop :-) I didn't find those when I was looking.

I've now installed the Tyco switch so I will leave it. Should it ever fail, I know what to look for now.

Thanks, guys

Posted: Mon Feb 24, 2020 8:51 pm
by maules.com
The rocker switches sometimes fail because the tail end of a pop rivet or drilling debris finally shakes down into it left over from radio tray installations or changes.
It is often possible to fish the debris out of the switch. The colored switch face can be removed from the switch.

Posted: Tue Feb 25, 2020 7:55 am
by jdsmaule
Thanks for the input guys! I have a lead on a switch, waiting to hear back once he can check inventory.

I had tried a few salvage yards and no luck. Those Piper switches look like a good match, just have to figure out the amp rating on those.

Regarding disassembly of the rocker switch that's what I did last year...after I had done some panel work prior. Popped the switch face off, sprayed some contact cleaner in there, couldn't really hear anything rattling around and started working fine. At least for a while.

Perhaps another go at taking it apart is in order, has to come out anyway!

Re: CB Rocker Switches

Posted: Tue Jul 28, 2020 9:29 am
by andy
Looks like my anti-collision light (strobe) breaker/switch has given up the ghost. I can't get it to switch on or mechanically lock in the on position. Jeremy mentioned that it's possible that some debris might have fallen into the switch and is preventing it from latching in place. My A&P is investigating that today but in case the switch itself is bad, I'm looking for a replacement.

I called Maule parts and these rocker-type breaker/switches are no long manufactured or available from Maule. They are using toggle breaker/switches now as jdsmaule and others mentioned.

Aircraft Spruce sells a Tyco W33-S2N1Q-10, which is a 10-amp breaker/switch like the E.T.A. 330826-12V in the Maule electrical system drawing but I can't get a datasheet on the dimensions of the E.T.A. switch to see if the Tyco will fit the cutout. My A&P is going to take measurements and send them to me today (I hope). I had to do a fair amount of Internet research to find the Tyco datasheet, which I found at https://www.te.com/commerce/DocumentDel ... F1393248-7 in case anyone is interested.

If the Tyco won't fit the cutout, then I'll have my A&P fabricate a metal plate with a hole to fit the toggle type Tyco W31X2M1G10 . It will look a little odd to have one toggle switch among the rocker switches so I'm considering replacing the anti-collision, landing light, nav light and pitot heat rocker type breaker/switches with toggle type breaker/switches. One single metal plate with holes could then be installed behind the panel for the 4 toggles. Has anyone done this?

Re: CB Rocker Switches

Posted: Thu Jul 30, 2020 5:52 am
by rv8bldr
That's what I did. I used the Tyco switch and made a small aluminum plate that spanned the the rocker switch gap (painted black so it blends in). Yes, the toggle looks different from the rockers, but it looks fine. Maybe make fancier labels :-)



Image

Re: CB Rocker Switches

Posted: Thu Jul 30, 2020 4:35 pm
by andy
The anti-collision light rocker switch/breaker is bad and needs to be replaced according to my A&P. He thinks that the internal spring broke and a repair wouldn't last. Maule sells a kit to retrofit all of the old rocker switches for around $346. They use separate toggle switches wired to circuit breakers. I don't want to suffer the cost and downtime of replacing all of the rocker switches so I decided to order one toggle switch and 10 amp circuit breaker to replace the one rocker switch. My A&P will fabricate an adapter plate to mount the toggle switch in the rectangular cutout.

I decided against the Tyco W31 thermal switch/breaker because of SAIB CE-13-22 and because Maule doesn't use them.

Re: CB Rocker Switches

Posted: Mon Aug 17, 2020 1:48 pm
by andy
Jeremy was right. A small screw fell into the top of the anti-collision light rocker switch and blocked it from latching in place. Although I mentioned this to my A&P right off the bat, he felt that the rocker switch was bad. So I ordered a toggle switch and separate circuit breaker from Maule. I'll hang onto them in case one of these rocker switches ever goes bad. I think the debris came from the Garmin G5 installation but there's no way to know for sure. I was skeptical about the rocker switch failing since the problem occurred when I picked up the airplane from the G5 installation. This is a heads-up to other owners. If one of these rocker switches fails, remove it and check for debris before you order a replacement. You can't see or remove any debris until you remove the switch and turn it upside down. I wonder if it would be a good idea to put some tape over the tops of these switches to prevent that from happening again.

Re: CB Rocker Switches

Posted: Sun Oct 11, 2020 10:25 am
by Andy Young
Late reply, but maybe useful to someone at some point:

I believe that turning the switches to the “ON” position closes (or at least reduces the size of) that opening at the top of the switch that allows debris to enter. I did that recently when drilling out my glare shield rivets.

FWIW, I also put a really wide piece of masking tape sticky-side-up just under where I was drilling to catch shavings, and tracked down each and every rivet tail.