View single post by Mark Rosenbaum
 Posted: 03-23-2005 10:55 pm
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Mark Rosenbaum



Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
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 To amplify John's comment just a little, a relay consists of two elements: (a) a set of switch contacts capable of carrying a "high" current, and (b) an electromagnet that, when energized by a "low" current, causes the switch contacts to close.  What a "low" current is, or a "high" one, depends on the application.

As John notes, the wiring that originally went to power the headlights would be moved to instead operate the relay's electromagnet.  This would reduce the electrical load on the lights switches by a factor of about 300.  A new wire, perhaps with an inline fuse, would run from the battery to one of the switch contacts, and the headlight would be wired to the other switch contact.

There are all sorts of different relay types available, so anyone not too familiar with car wiring, who wants to implement a system like the one John describes on his web page, would be well advised to follow his plan carefully.

Last edited on 03-23-2005 10:57 pm by Mark Rosenbaum