The key-in switch would please Rube Goldberg or that British fellow. But other than that, it's quite a clever design. It's a break-before-make switch with a cam profile built into the perimeter. The brass rotating contact has a cam follower on the end, so it gets lifted off the 30 contact in between switch positions. Thus it makes wiping contact with the brass terminal ends before the chunk of silver in the middle is lowered onto the silver 30 contact with a (very) slight rotating motion. It is *not* snap-action, so the speed with which it makes and breaks contact with the 30 terminal directly depends on how fast you turn the key. On the one I just took apart (aftermarket MWO brand, all white plastic) the silver contact connected directly to the 30 terminal was worn concave in the middle, a bit pitted, and the contact area covered with black "stuff," parts of which had a burnished appearance. Some of it wiped off easily and some did not. It's my opinion that this represents contamination from grease used to lube the switch moving parts, but I can't prove it. Turning off your loads before switching off (especially big inductive loads like the blower motor) would probably contribute to the longevity of the switch as there would be less arcing between the contacts as they open. Yours, David |
Please note - During the past 17 years of operation, several gigabytes of
Vanagon mail messages have been archived. Searching the entire collection
will take up to five minutes to complete. Please be patient!
Return to the archives @ gerry.vanagon.com
The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.
Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.