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> Heater Blower Motor, How to remove it for replacement
sburns1967
post Dec 3 2025, 11:27 AM
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I have a 1973 914/4 2.0 which is is partially disassembled.

It came with two hot air blowers:

Single Port - Working Motor
Dual Port - Dead Motor


In 1973 there was apparently a switch between the dual outlet blower to a single outlet with a Y pipe.

I was thinking I would like to use the dual outlet one so I thought I would swap in the working motor.

Two questions:

1) Does the dual outlet unit provide better heat flow through the heat exchangers than the single outlet with a Y connector? Any pointers to pictures of each type mounted/hoses?

2) How to remove the motor:
Removed the 6 screws on the motor flange
Removed the nut/washer from the cage fan

After doing so I can get zero movement from the motor from the housing. Even prying between the flange and the housing nothing moves.

Does anyone know if there is some kind of adhesive between the motor flange and the housing? If so do I apply a little heat maybe?


Thanks in advance
Scott


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wonkipop
post Dec 3 2025, 02:10 PM
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in terms of what the factory did with the blowers.
as noted above. single hose blower for 73/74 to drivers side heat exchanger.
single hose blower for 75 up to late nov/early dec 74 production date.
y junction adaptor to single outlet blower with twin hoses starts after that to end of production dec 75.

all of the blowers are parts bin components from the VW 411/412.

the early (70-72) twin hose blowers are from the 411 2 and 4 door sedans.
the 73-74-early 75 single hose blower fans are from the 411/412 variants (squarebacks) but without the squareback y adaptor. then later after nov/dec 74 using the y adaptor from the squareback.

when installed in the 914 the later twin hose set up used some stand off clips to keep the right hand hose clear of restricting the air flow to the cooling fan. i think this is an important detail. i have seen a few 73/74 cars that have had twin hose set ups installed by owners that lack the positioning clips and the hose restricts that gap that the cooling fan draws through. this was not an issue with the VW sedans/variant as the cooling fan drew air through a rubber boot and dedicated air duct in the bodywork.

as to why the 914s got only a single hose fan for a couple of years i would speculate that possibly it was felt beneficial to bias the fan forced air flow to the drivers side to assist with windscreen demisting in the small cabin of the 914 and ensure the driver side portion of the windscreen demisted faster. then later decided this was unnecessary.
its possible that the later style heat exchangers in the 75 models might have delivered more heat to the cabin than the earlier heat exchangers and the biassed fan boost was less critical for deep winter demisting. the exhaust system in that last year of production was itself a thicker guage pipe inside the heat exchanger acting as a kind of thermal reactor to deal with unburnt hydrocarbons as they exited the combustion chamber. it was designed to retain heat in the first section of exhaust pipe to burn those hydrocarbons and so probably generated greater heat inside the exchanger.

i am sure there would have been a rational reason they reverted back to a twin hose.
maybe what i put foward above.

in any case i have never found the single hose version in my 74 inadequate.
but l live in australia. hardly a severe winter climate. (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/beerchug.gif)
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