What are these, where to they connect too?

[Duke86]

I just bought this 1986 C10 and removed the old engine and installed a blue print 350 with no EGR stuff needed. I am trying to find out what these things are I have two with electrical connections on one side and what looks like vacuum lines on the other. I have so many questions. What are they? What do they control? Where do the Vacuum lines go? Where Do the electrical connections go.

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[Ricko1966]

Hi.

 

[Scott91370]

It has something to do with the transmission. Maybe the turbo350 but I cannot 100% confirm.

They are definitely not interior/heat-ac parts.

 

[hogdaddy]

ESC vacuum switch.

Whats this vacuum switch do?

On my 84 K10 I have it has a vacuum switch on the passenger side firewall that looks like the tc lock up thats on the driver side. When I got the truck I was surprized it would even start or move after I saw what was unplugged under the hood. the switch has a 2 pin plug in and should have a...

www.gmsquarebody.com

 

[TotalyHucked]

Was gonna say, I'm fairly certain that's either something to do with ESC or the TH350C converter lockup

 

[Jgonick]

passenger side- (yellow and brown wires) TIP -IN VAC Switch. Part of the Electronic Spark Control (ESC) system. You are probably not using that system anymore. What distributor do you have? The vacuum switch on the driver side by the brake booster is trnasmission related - 700r4 it is part of the TCC.