Wire issues are killing me!

[Chris' 86]

I bought my 86 Silverado a few months ago. The previous owner had already removed the majority of the smog crap that cloggs up the engine compartment. I was trying to figure out some issues with my gauges and I found some wire problems. I need to figure out what some of the connectors that are loose were connected to, or can I get rid of the wires all together. I will try to attach some pictures. Thanks in advance for any help you may be able to give.

[Chris' 86]

The rest of the pics:

[rwhit57]

I think that red one in pic 3 is a factory diagnostic plug, pic 4, I'm pretty certain is a vacuum switch for the convertor on a 350c trans. that needs a vacuum line hooked to it if it still has the 350c in it. The others I can't tell.

Oh theres more, Is that one 3/8 hose coming from the brake booster? If so it needs to go to the back of the carb. That broken sending unit on the intake is part of the old smog vacuum, if it's not leaking it's ok. Clean up the vacuum lines! Trace them or plug them.

[gchemist]

Vacuum switch on the passengerside is the ESC. I removed mine. The driverside is the torque converter lock up. You want to keep that one unless you have a locking torque converter.

[Chris' 86]

The pictures are a little misleading. The truck has a 305 with a 700r4 tranny. The person I bought the truck from gave me a set of valve covers w/ the gaskets attached. The existing covers were leaking, so the quick fix was to slap the new ones that say 350 on them on the truck. Being that it has the 700r4 does it need the switch on the driver side(hasn't been hooked up since purchased). The red one in pic 3 is half melted. It was sitting on the exhaust manifold. Any reason to keep it?

[rwhit57]

The red one is laying just about where yours is now on my truck. I'd just leave it. The 700r4 has to be wired up for the convertor to lock up. That switch could be used, but I would look and see whats plugged into the trans (driver side) and where those wires go. There are aftermarket lockup kits avail. If it is not wired up, your 700r4 isnt working right.

[Chris' 86]

Where does the vacuum line run to from the switch? Also, the line you thought was the booster line, isn't. It runs, along with the wire harness next to it, through the firewall. I have no idea what it goes to inside the cab.

[rwhit57]

Any ported vacuum is fine. I see the booster line now. Man previous owner did some weird stuff, I see vacuum hose going into the cab where the windshield washer nozzles should be. LOL Just keep tracing stuff.

[Chris' 86]

Originally Posted by rwhit57

Any ported vacuum is fine. I see the booster line now. Man previous owner did some weird stuff, I see vacuum hose going into the cab where the windshield washer nozzles should be. LOL Just keep tracing stuff.

The washer nozzles are both hooked up, so I'm not exactly sure which line your talking about.

[rwhit57]

Originally Posted by Chris' 86

The washer nozzles are both hooked up, so I'm not exactly sure which line your talking about.

Sorry I guess those are hooked to the nozzles.

[motornut]

Originally Posted by Chris' 86

The rest of the pics:

Attachment 783021

Attachment 783022

Attachment 783023

Attachment 783024

above the air cleaner orange port......Cruise control?
would also have a bigger hose to the brake pedal for the disconnect

you will find a air line from the same place(off manifold) to the heater controls
thats usally run through by the pass side

one of those open round sensors is for the tranny
and i heard of a sensor for differential pressure up there too on the firewall

[Chris' 86]

The truck does have cruise, but I don't have the carb set up for it. It doesn't go more than an hour from home, so there is no reason to spend the money to get the cruise working. As far as the brake comment, what is the disconnect for? It seems to me that since most things on the truck work, most of the stuff that is disconnected may not be completely necessary. I'm not as concerned with the vacuum stuff. Want to still know what it is, but I really need to figure out the wires.

[motornut]

the orange bit should go to the back of the manifold
for heater controls and there should be a hook up to the tranny sensor
from what i've learned/read the tranny sensor needs to hookup,bad without
the disconnect just tells the cruise to turn off when the brakes go on
that big line to the pedal can be removed
i've used a smoke (or insence)to check for vac leaks on sensors,some work cold ,some hot

[Chris' 86]

Any idea on the harness that is taped to the hose that goes to the pedal?

[motornut]

no sorry....hate the way pics shrink on here can't see

[motornut]

this may help it's tbi but simular hook up
fix the vac leaks it helps gas mileage

[cr34t3d_by_d4rkd3n]

hahaha been there done that game, do a search for my user name of all posts ive posted and ull see several posts containing detailed wiring diagrams.

hope u figure it out.