92 Subaru Legacy Windshield Defrost Kills Engine @ low RPM

[woodburnbob]

I was slowly going down a relatively steep urban grade in the snow...at
low RPM. The engine stopped and took steering and brakes with it. I
stopped with emergency hand brake. A little tense for awhile.

From then, idling or low RPM leads to engine dieing if, and only if,

the windshild defrost is put ON. Headlights and rear window defrost
are off. At idle, the RPM bounces erratically back and forth from 200
to 1500 and the engine dies after about 20 seconds unless I "give it
gas" and get the RPM about 1500 or so. I hear cluncky clicks from
right center of dash sometimes while the dieing is going on.

I take it that something has failed. Any ideas what has failed?

 

[strchild]

Check your air conditioner compressor. Defrost runs the compressor to dry
the air going to the windshield.

~Brian