[MAC71]

Going off of the advice of one of vintage airs authorized dealer/installers , Roger Lewis Makeover in Pearland TX, this is how mine is set up.

The lines for the rear or only T'ed of in to places at the # 4 line coming from the condenser (in photo) and T'ed of on the compressor on the suction side( in photo. That is all I had to do. So only addition to the system other than the rear A/C unit are the hoses from rear to front and the T fittings. So no additional dryer.

Before I did this conversion I did do lots of research on line and found confliction information on if a 2nd dryer was needed. I in the end decided to go off of the dealers advice and went with one dryer.

Also because the systems are operating together that also requires the blower fan to be on at the same time, as in if the rear is on the front fan also has to be on, and if the front A/C is on than you have to have the rear fan on. If not the evaporator coil will externally freeze up.
There are solenoid operated refrigerant valves that can be places inline the high side leading to the rear to isolate and shut off the rear A/C. I did not personal price them but were told that they were a few hundred dollars from a dealership. Decided to go with out it, but looking back I should have investigated this more and I may at a later time add one in.

As far as part numbers for the T valves I don't have any, but the place I got them from was South Texas truck air 713-675-2700. If I was currently in the states I would call and try to get more info for you. But it should be easy to find some where the specializes in truck(18 wheeler trucks) or R/Vs because these vehicles have mutable A/C units in them.

Also the type of compressor that I have is a 600 series as in the Sanyo 605 that comes with the chevy truck direct fit A/C kit. There is a larger capacity unit that is a 700 series, but to keep the price down and because the dealer also thought that the 605 would work I kept the smaller 605 compressor.

Let me know if you have any other questions.