[Slick]

The original hood scoop wiring and vacuum controls were mucked up by a previous owner. I'd like to restore the "hood air valve" to proper operation.

Read Rocky Rotella's article about shaker scoops in Hot Rod, online. So, if I understand correctly, the vacuum controlled relay inside the scoop is fed 12V through a passenger side cylinder head located thermostatically controlled switch. That relay, in the scoop, is fed manifold vacuum so that the air valve only operates when the engine is over 140 degrees and manifold vacuum is at a minimum. The relay feeds 12V to the air valve solenoid when the engine is warm and throttle is depressed. Makes sense.

The air valve solenoid, vacuum switch and scoop mounted bulkhead connector are in place, in my car. But that's where I lose it.

Looked in my 74 Service Manual and saw vague references to the "hood air valve", but not much else. The thermostat is allegedly fed from a point "A" with a yellow wire. The other side of the thermostat goes to the scoop vacuum controlled relay via another yellow wire, along with a ground, to the 2-pin "T" form connector.

I can't find point "A", the thermostat or yellow wires on my car. Some previous owner made a crappy little harness from two 1/4" quick-connect flat blade connectors and a couple of pieces of #14 AWG.

So my questions are thus:

• Where is the 140 degree thermostat located? Exhaust side, or rear of the head?
  • Where is the source of 12 volts, point "A" (where lots of under hood engine wires connect)? It's not at the alternator, but I suppose it could be a soldered connection inside of the engine wiring harness.
• Does the switch actually have two yellow wires connected to it? The thermostat on the back of my passenger head has two different colored wires, neither of which is yellow.
• Has anyone experimented using an oil pressure controlled switch on the negative side of therelay wiring circuit? It would be necessary to find a normally open pressure switch to fit 1/4" or 1/8" pipe threads in the engine (at the distributor). The typical oil light switch is normally closed; i. e. closes contacts on pressure drop. I'd like that better than the thermostatically controlled switch.
  • Is the scoop bulkhead connector available anywhere?

Thanks!

Stuart