Heater/Air Con

I am fitting an under dash/firewall mounted Heater/Air Con unit from Classic Auto Air.  It is the Street Rod II unit, Classic Auto Air make and supply perfect fit systems that replace the original units, but I wanted to mount the unit slightly differently and also wanted electronic controls rather than cable.

The evaporator unit looks like this:

It has servo motors to control the flaps for air control and the water and refrigerant connections are inline parallel with the bulkhead to allow for positioning of the bulkhead connectors where required.  It looks like a well made unit made from good quality materials and parts.

The evaporator is only one component of the full Heater/AC install, as well as this a number of other components are required.  Other than the wiring and Head unit controls that I also got along with the evaporator I will either be using what I have or sourcing the other components here in the UK.

The in Dash controls come in various designs, I went for the polished Aluminium Oval design as you can see here:

I have used this design (the Oval) throughout the interior.  All of the Billet items including the A/C Vents, Air Ride Control, interior Lights etc are all the same profile.  I didn't want anything square.


The other components required:

Compressor - The compressor is already on the Engine so I will be using that. 

Hoses - The hoses I will get made up locally once I work out were it will all route neatly. 

Condenser - I will source this in the UK from one of the various places selling A/C Components and fit it in front of the Radiator. 

Drier - I will source this in the UK from one of the various places selling A/C Components and fit it next to the Radiator. 

Bulkhead Fittings - I am not sure what I am doing regarding the Bulkhead fittings at the moment, I like the idea of hiding the Hoses etc as much as possible to keep the engine bay as neat as possible, but I think it will be difficult.  The other option will be to purchase a nice bulkhead plate that includes all 4 fittings in one neat package.  There are various types available in different configurations.


When I came to test fit the evaporator unit, I quickly realised that I would have to modify the Bulkhead (Firewall) to enable it to fit in the desired location.  I am mounting it on the passenger side of the firewall behind the glove box.  Only problem is that the firewall is not flat where it would need to mount.  So I decided I would have to cut a section of the transmission tunnel hump and flatten it out.  I made 3 vertical cuts in the hump with a cut along the bottom, then did a bit of hammer and dolly work to straighten it out.  I then welded some new metal in along the end and the bottom to complete the mod.

After finishing the front bulkhead modifications ready to mount the A/C Heater unit I had a bit of a nasty surprise when I came to offer it up to the mounting holes to test fit it.  I am not really sure how I managed it, but I failed to take into account that the unit has a deeper section that protrudes in from the outside edges.  So when I pushed it up to the mountings it went up to the point where it fouled on the middle section before the mounting holes lined up.  I picked up the angle grinder with a slicing disc on it and made a cut through the bulkhead about an inch below where it actually needed to be cut.  I decided that I would rather cut out too much than mess about any more.  I then fabricated a small triangular section to fit in below the the original cut-out.  You can see the end result here from the inside and from the engine compartment side of the Firewall too.

Once fully welded in place I offered up the A/C Unit and bolted it in place as you see here.  Due to the location of the A/C Unit, there will not be much room for the glove box or the wiper mechanism under the dash.  I had to cut and modify the passenger side wiper arm to put a slight kink in it to clear the A/C unit.