Anyone know where this vacuum hose comes from?

[Fast Eddie B]

This is on my 77 wagon. It is the Water Valve. Cleaning up the engine bay. Heater and AC have been working inspite of this hose being disconnected.

FSM says that the line comes from under the dash from a vacuum switch but I can’t find where it passes through the firewall. Can’t find a vac hose or a hole it might be coming through.

 

[Mr C]

Just checked on my 77 T&C...although mine is Autotemp II it should be the same spot.

Look under the wiper motor...about an inch above the pinch weld on the firewall....right across from the oil pressure sending unit on your B/ RB.

 

[Fast Eddie B]

Thanks. I’ll check when I get back this aft.

 

[71NewYorkMan]

Heater and AC have been working inspite of this hose being disconnected.

This valve turns off water flow when your control is set to "off" or "max AC", thus being disconnected it would allow water flow at all times.

 

[traintech55]

When you find where it comes through the firewall, it will be in a grommet with two PLASTIC hoses. The black hose is from your intake manifold and is vacuum into the system. The gray hose is the one that goes to the water valve. most of the time these plastic lines break with age, just install a small diameter vacuum hose to connect it to the valve.

 

[Fast Eddie B]

Great. I found it. The worlds smallest vacuum hose. I found it earlier. It was sitting in the exhaust manifold. All melted. I thought it was a burnt wire. Figured it was something old and disconnected from the old Lean Burn. Clipped it off.

well.... when I saw the comments above and found the two ‘wires’ coming out the firewall, I found the piece I cut, stuck it back on, all good now.

here’s the funny part. When I found the old dead ‘wire’, I was going to past a pic of THAT and ask what it was!

 

[75LandYacht]

Gonna highjack your thread for just a Sec Eddie

I need help identifying this piece (Little White Box) on the pass inner fender of my 75, it’s Oozing and I’d like to replace it. Thx

 

[78Brougham]

That's a timer for an emissions related switch. EGR perhaps. John

 

[Fast Eddie B]

Oozing is pretty freaky. Overheating?

 

[78Brougham]

They're known for that. No big deal really.

 

[DC118us]

They're known for that. No big deal really.

Oh that's good to know, I think every electrical box under my hood is oozing like that.

 

[78Brougham]

The only ones to really concerned about are the electronic voltage regulator, and the electronic ignition.