Yes, they are interchangable.
I have been swapping the AC fans into the front heater for many years with no issues.
Most of the AC systems I have taken apart were barely used and the fan motors were in excellent condition.

Plus the AC units in 7 pass. vans have two fan motors.

dylan

________________________________
From: mark drillock <mdrillock@COX.NET>
To: vanagon@GERRY.VANAGON.COM
Sent: Saturday, February 28, 2009 8:45:00 AM
Subject: Re: Front/rear blower motor swap from AC unit?

I have noticed this myself. Recently I was helping a relative to replace
his dash heater fan and we side by side compared it to one of those A/C
fans. As far as we could tell they were the same other than the trivial
wiring connections. We tried both, running them on all 3 speeds and
could not tell any difference.

The A/C fans live in a much more protected place and I suspect lots of
us will end up using them in our dash heaters down the road.

A web search showed an aftermarket fan replacement to fit both
applications with the same replacement part.

Mark

Max Wellhouse wrote:
> I recently took apart a cracked rear AC housing from the 86 Syncro
> and noted that the twin blower motors in there look a LOT like the
> single blower motor that's used in the front heater set up.� These
> wouldn't happen to "swap in directly" now.......would they?
>
> thanks
>
> DM&FS
>