1 hour ago, TomoHawk said:

It should only have 12V after about 10 seconds, if the thermotime switch is working correctly.  Otherwise, it should have 0 volts when you first turn on the power.  In any case, test it under a load.

His problem is with the AAR, not the thermotime switch.  The AAR has power as long as the fuel pump has power. 

 

I know this sounds stupid, but is it possible I have the ARV plugged in backwards ?

It is just a heating coil inside. 12v one side and ground on the other. Here is what it looks like inside on the electrical side. I put mine in the freezer and looked inside to see how far open the port was then I heated it up in a shallow pan of water to see how far closed it went. 

I did an OHM check on the functioning one on my 81 and it shows 40 OHMS. The one in the picture has an open circuit so it is dead. 

 

20 hours ago, Killain said:

I know this sounds stupid, but is it possible I have the ARV plugged in backwards ?

It's a coil (much like the filament of an incandescent light bulb in this case - the filament itself doesn't actually care which way the electricity flows) so it'll work as long as one side is battery voltage and the other side ground. You should be able to see it work when it gets voltage if the hoses are disconnected. You can look through the hose connections and see the shuttle. It should be mostly open when it's cold and has no voltage. Once it has voltage, the coil will heat the bi-metal strip and cause it to bend, which moves the shuttle slowly until it closes the port. It takes a couple of minutes.

Edited June 23, 20222 yr by cgsheen1

Thank you both, I'm getting the feeling I have a 'Vacuum Leak' and it is just somewhere I haven't been able to either slow the engine down so I can check for a visible or audible vacuum leak, once it's fully warmed up is seems Ok, but . . . 

Check the intake manifold to head bolts/nuts, the end ones have a tendency to break off and the EGR valve flange.

1 hour ago, Killain said:

once it's fully warmed up is seems Ok

That would be because the coolant plate underneath the AAR has heated up.   That means that the valve is not binding.

All signs point to no electrical power through the AAR heating coil.

Unlikely that a vacuum leak would disappear when the engine warms up.

Just trying to be helpful.

What is the AAR ?  I'm not use to that part ? The Air Regulator Valve just bolts to the intake manifold ?

Some sources call it the Auxiliary Air Regulator.  AAR.

If you look closely at where it attaches you should see a plate underneath it with heating cooling lines attached. 

Edited June 24, 20222 yr by Zed Head

Aux Air Regularor.....Aux Air Valve same thing. It sitson a plate that is bolted to the intake manifold and antifreeze flows thru to help it heat up and close sooner. Look for the small hoses below the AAR.

Hoover's...