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
>