Roadmaster Wagon Rear A/C

This car is an RMW with the C68 fully automatic climate control. There is no recirc button. The recirc function is only commanded in maximum cooling mode -- either when the CC decides the interior temperature is sufficiently higher than the commanded temperature to warrant it, or when the commanded temperature is set to the minimum (15°C/59°F).

Unfortunately, while recirculating the air does tend to lower the vent temperatures, it actually reduces cooling to the middle and rear seats. In normal operation, outside air drawn into the car causes a slight increase in air pressure, causing the pressure relief valves next to the middle-row seats to open. The resulting air flow draws cool air from the front seats rearward to the middle of the car. However, when recirculating, very little air is drawn in from outside, so very little air exhausts. Most of the air simply circulates around the front seating area, leaving mostly dead air in the rear half of the car. This can be alleviated by pointing the dash outlets upwards so that the air tends to blow over and around the front seat backs and return along the floor under the seats.

However, there is no mode that draws air to the third-row seating in the wagon. Because the pressure relief valves are next to the centre row of seating, and there is no return path below the seats: the third row is in dead air. Opening the rear vent windows helps when the car is moving but with the long, dark roof the air that does get there has warmed by the time it reaches them. Too bad they are manual - the little guys can't reach them when belted in and you don't want them open when it's raining anyway.

Rear AC (and heat in the winter -- it can get down to -40 around here) would be the best solution, but the other idea I had was to cut in a pair of 12v computer muffin fans somewhere under the rear speakers. With a corresponding pair of exhaust vents somewhere in the vicinity of the middle row seat cushion, it would help the rear passengers somewhat. It still leaves me freezing up front though.

http://www.oldairproducts.com/catalog/underdash-ac-systems-400-series/old-air-products/ip-400hc/underdash-unit-inside-package-p-4487.html

This is a nice looking underdash unit that might work for our cars.

My 94 silhouette had factory rear ac. It was in the side. Worked well at cooling the whole thing.

I have an 04 Express van (3500) with rear AC and heat. Works like a charm. It is small enough to fit in the rear cubby holes.

I have a pair of rear Caddy air ducts if anyone needs them.

Other possible ideas according to RedneckAC.com





portable version

Great pics! I appreciate ingenuity, even if it is sometimes 'misguided'.

well guys my wagon maybe a little bigger and doesn't seal weatherwise good compared to your newer car's ,so here is just my 2 cents. originally had a vintage air in dash with a monster cooler but it just couldn't really cool the car ,left the indash added an old style underdash ,split the lines and you would think you could make ice cubes

That's why I bought an Astro minivan with DUAL A/C !
Wanna buy my wagon?

Those pics are great!

super old thread here but did anyone ever do anything with this idea? I was googling and it brought me back to his posts.