The gurgling noise is probably air in the coolant. Mine does that after coolant has been changed. The best way to handle that that I've found is to fill the coolant tank nearly to the top. After a few heat up/cool down cycles this will generally purge the air.

RE: fogging windows, this is a common problem with aging climate controls. Mine also does that, since it sends air to the defroster vents when first started before the vacuum servos have a chance to route the air to the AC vents.

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Steve
'93 400E