Heater blower fan outlets, school me Options

[stateofidleness]

Gents,
I have a VERY original '73 1.7 that I am just now able to give some attention to. I wandered to the "dark side" of the forum (Originality (IMG:style_emoticons/default/biggrin.gif) ) and noticed a lot of great engine bay pics. A lot of them have a "dual outlet" heater fan in the engine compartment that has plastic tubes going to both sides of the engine. On mine, it is mounted on the driver's side engine shelf and only has a single plastic tube that stays on the engine side of the compartment.

Can yall school me on what year models/engine sizes/options determined the heater fan setup and if mine is correct or not?

Thanks!

[442nd914s]

I read somewhere that early models had single outlet going to the divers side (pre74). The passenger side was caped off. Late models '74 on up had 1 long accordian style (passenger) & 1 plastic hose (drivers). My 1 owner all original '73 2.0 lt was set up with only 1 plastic hose single outlet & passenger side caped off. I changed it to a dual outlet 2 hose set up after reading that 1 outlet may not be enough for defrost. Hot air will NOT come through the dash vents. Only by windshield & feet. Vents are for fresh air coming from front cowl.
Hope this helps. I remember I found it under "heater duct", but for some reason I cant find it.