Todd,
If memory serves me;  the compressor clutch only has one wire. Twelve
volts is applied to this wire to energize it. You do not need a relay.

 Here is a useful link: http://www.theledlight.com/ledcircuits.html

While you are at it, I would also hook up LEDs to indicate the status of
the high and low pressure switches. This would give you useful diagnostics
information.

Ken Lewis
http://neksiwel.20m.com/

On Sat, July 25, 2009 5:37 am, Todd P Last wrote:
> I want to add an LED indicator on my Vanagon that will show when the A/C
> compressor is engaged.
> Has anyone done this?
> I'm thinking that I just need to use one of the wires on the A/C clutch
> to connect to a relay to activate the light - but I don't know what wire
> to use.
>
> Anyone have any suggestions?
>
>
> Todd
> '88 Westy
>
>