My underhood light had not worked since I bought the car several years ago (it was pretty rusty among other things). So today I put in a new assembly, which I've had for a few weeks. It was straight forward and I was able to swap it out to the harness connection the other one was connected too. I had assumed a toggle switch  on the passenger side firewall was the trip switch...lift up the hood it would go on and had been disconnected since I owned the car. Anyway I put in the light bulb and pop the light comes on! Now I'm confused since I didn't connect that toggle switch. I like to know where the right switch is, cause all I have to do is close the hood and the light goes out. Or open the hood and as I lock it in the open position the light comes on. I cannot find a switch that the hood or struts might be connected. I'm concerned as I would prefer to be able to keep the light off while I'm showing the car. I know I can disconnect the bulb or the connection at the harness but I guess I'm a perfectionist and want to know how this sucker is working.

I have the huge trouble shooting wiring book for the 78 vette and I cannot find the underhood light mentioned in the drawings. I'd also like to know what that other toggle switch is for as everything else seems to work on the car, except the AC.

Anyone have an idea on either? Thanks

Late edit: the toggle switch is not toggle, but a plunger type of switch. Sorry for any confusion. 

I believe the underhood lite uses a mercury switch to activate it.  Is the toggle switch that you mentioned OEM or aftermarket?  It might be an ignition kill switch if it's not easily spotted.  Otherwise you'll need to track the wiring down.

1973 L-82 4 spd

That makes some sense, because I can rock the hood and the light will flicker on and off. Would love to know where it's at though. The other switch is actually a plunger switch (not toggle...my bad). It's standard because I see it in manual pictures, but as background. Thanks!

I did find the switch/light for the hood in my book, don't know if it's helpful, I'm not a trained electrician.

That's the mercury switch inside the lite housing.

1973 L-82 4 spd

The plunger switch you found is probably for the alarm.

@73shark - If it is, it's the smallest switch ever. There's just doesn't seem enough room with the size of the unit holding the socket for the light. But that seems to be a possiblity for sure. I still have the old one, think it'll take it apart, if possible. Thanks

@F4Gary - could be, I'll try opening the hood with the alarm on. I know the alarm works with the doors, so we'll see. Thanks.

1973 L-82 4 spd

@73Shark - you nailed it. I went back to the vendor site and in the description, besides the wire etc it included the mercury switch. Many thanks!  I've yet to test out the other switch. But thanks again. 

I'm sure you'll find that the push-button switch is for the alarm.  Our alarm doesn't work so I can't test ours, but we have the switch! 

When we bought our '78 (in 1990) I was concerned that the under-hood lamp might staying on when the hood was closed.  Like you, I couldn't find a switch for it!

So, I installed a small toggle switch in the circuit, adjacent to the lamp.  That allows me to have the lamp on or off as required, and I know its off when I want it off!😄