Hi all--

I've got a new (sitting in the box for a year) American Jetted Bathtub that came with an inline heater already installed and a new pump (G&G Industries Olympian HE) in a box. All wiring was done at the factory, as was all the plumbing except the pump hookups. The instructions relating to the air switches for the pump on/off and the speed selector said simply "connect air hoses to nipples on pump".

Now, I'm normally pretty mechanically inclined, and I know some plumbing and electrical, but I can't for the life of me understand where these connections are to be made, and how. There's two air hoses hanging down from the switches built into the tub wall, one is about 3/8 or 1/2" outside dia (goes to the power switch) and then there's one much smaller, maybe 1/4" OD from the speed switch.

There's a fitting on the back of the pump electrical housing that is threaded on the outside, where I would assume the larger hose connects-- but how? It's too small to go over the threads (unless I really forced it!), but there's no fittings included that would thread into the hose to make the connection.

Then there's the question of the smaller hose-- no clue whatsoever on this one! There's three "nipples" on the wet end of the pump, but none look like likely candidates-- and I can't understand the mechanics of how these things would control the pump speed anyway.

Any help GREATLY appreciated!!

Where does the speed switch connect?
Top view
I think this is where the on/off goes

Nice looking unit!
The connection from the top of the shell will go to the "Air Switches" located in the control box.
( On Off ) Air switches (latching) are a bit like Bic Pens. As they are subjected to a puff of air pressure, the diaphragm pushes up an auger to latch in an upward position. This in-turn pushes a micro switch. Thus off on. The threads serve to fasten to the housing via the plastic nut. There should be a nipple right in the center to accommodate the air tubing. If not, it may have been yanked off.
Momentary will bump a set of points via the diaphragm. Either way, there is a nipple involved on the receiving end of the air switch.
The other nipples on the wetend (ABCD) serve to vent the plumbing, or feed a circulating system,
(for kinetic heating retrieval) etc. A & B are on the discharge side, C&D are on the suction side of the circuit.
If they are not tapped out (plugged), then they are not of any concern.

Don't work on a lot of jetted tubs.
Maybe someone else will chime in on this one

thanks for the reply! after reading what you told me, I went out and had another long look at the system.

as it turns out, the nipple marked D was bored out, and it fits the larger diameter tube perfectly. I still don't get the mechanics of how this pressure bump can change the speed of the pump, but I'll take your word for it.

thanks for your help