D1 Mystery attachment? What is this cable for and what bolt size thread is it?

[El Ed]

I have a 95 D1 and I found a connector missing the bolt. I don’t know what this is for but it looks like it attaches to the bottom of the block right next to it. Can someone tell me what it goes to or what it is? It’s a flat metal connector with black insulation and is almost below the AC or pulley tensioner? I can’t get a clear view form above or below.
Thanks for any input. Eddie

 

[robertf]

You are missing a socket head cap screw. It clamps the heater tube to the engine. I believe its 1/4-20 thread around 1/2" long.

 

[El Ed]

You are missing a socket head cap screw. It clamps the heater tube to the engine. I believe its 1/4-20 thread around 1/2" long.

Thank you Robert!