[AT] What is a Relay?

[Phil Auten]

Ricky,
You wire the relay coil up to the light circuit and then use a heavy wire 
through the relay contacts hooked to a fused 12V source
to run the lights. Then, when you turn on the lights, only the current for 
the coil goes through the light switch. That is usually 1 Amp or less, 
depending on the relay. Be sure to check the current draw of your trailer 
lights, including the brake lights, and get a relay
with contacts that will handle at least 50% more than needed in case of a 
problem. That way the fuse will blow and the relay won't melt or weld the 
contacts.

Phil

At 09:03 AM 12/10/04, you wrote:
>How does a Relay switch work?  My lights on my truck went out.  It burned 
>up the plug that goes into the switch.  I rewired it. My Mechanic said I 
>need to install a relay so when I hook up my trailer lights it won't burn 
>up the plug again.  I am wondering what I need.  The wiring in the  old 
>dodge is not heavy enough to handle all the amps the trailer lights 
>draw.  I hope I made this clear.  Thanks, Ricky