Heater facia

[wbute]

Forced air meant the cab had air forced through it as you drove along. Non forced relied on the fan to allow air into the cabin. As you can see the forced air has the vent image on the facia and the non forced does not. So when you place the control to the vent position outside air can enter un-assisted.
The owners manual explains the system.
I think but may be wrong, the air vents on the B pillar on a commercial and the C pillar on the sedans/wagons may also be different between the two?

[Dr Terry]

I always believed that the main difference between the 2 systems was that, with the standard set-up, the only fresh air available at face level, was at the 2 outer vents & it only entered by virtue of the car's forward motion. i.e. the faster the car went the more air you got.

'Forced air' added fan-forced air to the 2 centre vents. This made room temperature air available while the car was parked or traveling slowly in traffic. Yes, you got more air forced in when you drove faster, but the fan-forced bit (or fan assistance) was the main advantage.

I seem to remember it also being referred to as 'power ventilation' in advertising back in the mid 70s.

Not sure about the exit vents in the B-pillar being different, I will have to look into that one.

Dr Terry

[wbute]

You are correct Dr Terry. Just re-read the owners manual.