Page 1 of 1
Light switch repair
Posted: Mon Oct 26, 2009 9:46 am
by TomM
Where can I get tech drawings for the M-series light swith?
I have one apart that wasnt working due to corrosion on the contacts. Once cleaned, where are the 4 pins oriented in their spring sockets for assembly?
They look like:
Round part pointing out from center.
Long slider rubbing against inner continuous track.
I'm looking for a drawing showing where the single and double contacts should be oriented in the off position.
Tom
Posted: Mon Oct 26, 2009 1:25 pm
by wesk
Tom,
I sent you some photos.
photos
Posted: Mon Oct 26, 2009 1:51 pm
by TomM
Thanks Wes
Got them.
Thats exactly what was needed.
Tom
Posted: Wed Oct 28, 2009 12:08 pm
by hill
is there any one that sells parts for the early M series headlight switches the one I have has been gutted and missing the back and screws
Posted: Wed Oct 28, 2009 1:25 pm
by wesk
I don't know of anyone selling new or NOS parts. What you have to do is download or copy the entire parts list from the M38 ORD 9 and orhanize it either alphabetically or by part number or stock number and then google individual numbers. You can also assemble a needed parts list and send it to all the surplus dealers.
Posted: Thu Oct 29, 2009 5:28 am
by hill
thanks for info if you can would you send same photo of switch thanks
Posted: Sat May 01, 2010 5:16 am
by taskerman
I have to attempt the overhaul of a light switch and would appreciate a copy of the pictures if possible.
Thank you
Posted: Sat May 01, 2010 10:39 pm
by wesk
The photos are for the early Scintilla switches that have exploded views in the ORD 9 parts list. These were repairable in the filed.
The later Unicite and about 5 other manufacturer's versions were consider a throw away item in the Military supply system and internal parts were not supplied for them. Your only hope with the late switches are if they have a reusable rear retainer ring or feature so you can open them up and then re-close them after you have has a chance to make any feasable repairs or contact cleaning and lubrication that you may have had resources handy to complete.
Posted: Sun May 02, 2010 9:19 am
by taskerman
Thank you for the Pictures. Mine is the ucinite version so it looks like I willl have to try and force the two pieces apart.
Roy
Posted: Sun May 02, 2010 11:10 am
by wesk
I think if you apply a very small concentrated amount of heat at each of the bent tabs and you pry each with a screw driver just a little just as the heat is applied you can prevent breaking them off and if careful with the heat you can avoid melting any of the plastic or phenolic material inside. They do not have to glow. Just need to get the uncomfortable to touch. A high output heat gun would be a good tool to start with.
The next brand of switch was the Pollack switch which I believe is about the same internally as the Unicite but they use a snap ring to hold the case halves together.

Posted: Mon May 03, 2010 6:57 am
by taskerman
My thanks for the additional pics & the tip on opening it up. I'll let you know how I get on.
Roy