Re: 5KCSTQ Fan Issues

[Wallace White <wallace@remdesign.com>]

Richard -

> I checked the fuses, etc. for the fan -- no burnt fuses.  Also, I noticed
> another part humming when the engine is off.  It's some type of pump
> located directly behind the rad fan-- with hoses going to and from the
> radiator.  It's about the size of a really thin coup can laid on its side.
> It's directly behind the rad fan--  in fact, it's so close, it looks like
> it may get hit by the fan blades if it were any closer.

That's the auxiliary water pump, also called the turbo coolant pump or
after-run coolant pump. That's right, it's supposed to run with the
radiator fan after you shut the engine off, if the thermoswitch is
closed. The after-run relay turns on both the aux. water pump and the
rad. fan 1st stage together from the same pin; if you're hearing the
pump run without the radiator fan, something's wrong with the radiator
fan, its relay, resistor packs, wiring... but not the after-run relay.
HTH.

- Wallace
  '87 5kcstq 153k