markejackson02 Posted June 24, 2017 Report Share Posted June 24, 2017 The press-to-test switch for my annuciators broke during an avionics install. One of the lugs on the bottom. It is an ALCO (now Tyco) MSP205R switch. A DPDT switch. Not made any more. Also, no info on the switch connections. I think that the replacement is an MPA206R. Anyone know if this will work or have any idea how to test the terminals so I can figure out what wires to connect where? Thanks very much. Quote Link to comment Share on other sites More sharing options...
LANCECASPER Posted June 25, 2017 Report Share Posted June 25, 2017 Maybe look for another annunciator on ebay. Quote Link to comment Share on other sites More sharing options...
M20S Driver Posted June 25, 2017 Report Share Posted June 25, 2017 is this the same switch on ebay? It is a bit confusing since the part number is the same but it says 115V!! https://www.ebay.com/p/Alco-MSP205R-Pushbutton-Switch-5-Amp-115-VAC/671619609 Quote Link to comment Share on other sites More sharing options...
Steve W Posted June 25, 2017 Report Share Posted June 25, 2017 (edited) DPDT switches are pretty easy. Take an ohmmeter(or a continuity checker) and measure from the center to the top and bottom in the same column. One will show 0 ohms(the test light will go on) when it's not pressed and one will show 0 when it is pressed. 1 4 2 5 3 6 So, you'll see 0 ohms(continuity) from 2 to 1 and 5 to 4, at the same time, or 2 to 3 and 5 to 6, and when you press it you'll see the other set, match this to the new switch and all should be fine. If you look at the spec sheet from for the MPA-206 you'll see this described. http://www.mouser.com/search/ProductDetail.aspx?R=0virtualkey0virtualkeyMPA206R Typically voltage ratings are maximum, so 115V is fine. Edited June 25, 2017 by Steve W Quote Link to comment Share on other sites More sharing options...
markejackson02 Posted June 25, 2017 Author Report Share Posted June 25, 2017 Yeah the ebay ones were all not the same switch. I ordered an MPA-206 and will also order a MSP205R from a salvage yard. I like ordering plane parts that are sub $10 :-) I was able to figure out the switch function with a multi-meter. Learn something new every day. 1 Quote Link to comment Share on other sites More sharing options...
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