No hot air in a 420G

Saloons
1

All parts and functions appear normal, but
I dont get any hot air inside.
The small, wire operated valves on top of the heater element, also look like on my other cars. I can see and hear what seems to be the opening and closing of flaps.
All vacuum functions are fine. The incoming and outgoing hoses to the heater are very, very hot.
I just dont get itā€¦Not even a hint of hot air insidešŸ˜±

2

I just saw in the Parts book that there are R and L side fans. Perhaps mine are mountedon the wrong side, thus preventing hot air from entering the interior of the caršŸ˜±

3

almost certain they have either arrows, or white L and R on them, I will check a complete unit I have later to see if I can see where the marks are

4

And while I at it: one of the 2 fan motors on my blue G has not been wirking for a couple of years. Is there an obvious fix here, or just buy a new one, if they are available?

5

Can you attach a vacuum sucking pump to the lines to see if you might have leaks under the dash. Once you know you have a good vacuum source, the vents should open and you would have heat. Or do you have the wire operated controls and they might be completely plugged up with gunk. Is your hood ram air vent open?

Isnā€™t there a trick with cigar smoke which you could light inside the car and pull vacuum under the hood to make sure you have smoke (not Lucas style)? Others please chime in. We canā€™t have Peder freezing this winter. I recall my MK10 had a toasty heater.

Let us know.

Gerard

6

It turs out that the vacum heat valve, just behind the intake cam cover, works the opposite way. If I remove the thin tobe/hose, hot water flows into the heater box, and I get hot air inside the car.
It is a later, moden valve, probably for a different car.

7

my heater is disconnectedā€¦howeverā€¦

On 420G, the heater valve allows water flow, when vacuum is applied

ā€œmodernā€ valves can work either way

if it was ā€œoppositeā€ you would have had heat all the time, as vacuum closes the valve

as long as it works for you!

Where I live in Australia, having the the hot coolant run thru the heater core at all times is not ideal with airflow design