a couple of questions for you 80's trucks guys

[mike reeh]

two electrical boxes I found when parting out this 80 something cab and Im wondering what they do:

one is screwed to that square metal trim peice that completes the dash, below the steering column. its got a big aluminum heat sink on it and it has many wires going thru

the second one is a yellow plastic box, with 3 wires going thru, and the wires go right to guage clip, right next to the speedo cable input...

any ideas?

also I want the intermittant wipers box and stuff, where should I look and what all do I need? Ill be keeping the column.

I may have some good used parts of this cab that I wont be using so stay tuned.

mike