Need some help.  My 78 came with the underhood lite but, its long gone(still had the ground loop when  I bought it). I want to replace it. Eckler's has an after market one. My question is where does the wiring go from the lite down to the conector.  I found where it connects to.  My first vette an 81 had  the lite but don't remember how it was hook up. Any pic would really help. Thanks for any help.

The underhood lite is mounted on the Drivers side of the hood, as you look at it from the Drivers seat.  It has a mercury switch that caused the lte to come on when the hood is lifted. Send me a pm with a good phone number for you and I will call you with more info!!

While I see this post is dated,I had a question about that underhood lamp too.My '82 Collector asked for a bypass switch for the lamp,I see there are two versions,single terminal or dual. They also list the dual as '80-'82,the single '77-'82.I want to get the right one, I don't want to yank the wrong cord.Is there an easy view to the connection? It's alittle tight along there. Ken

I'm confused...a switch, by design, will have at least two terminals.
I think the late cars did have two wires going to the light(power and ground), where the earlier cars only had a power wire to the switch. The aforementioned mercury switch would then provide the ground side of the circuit when the hood was raised. It really depends on how you want to do it. All you need is a simple on/off switch, cut the power wire going to the light, and splice in the switch.
I'd say if you are purchasing the switch, go for the "dual terminal", and it should plug right in.