My 1992 Legacy L Sedan has a problem, if I let it idle for say 5-10 minutes with the heater on, the radio will all of a sudden die then the engine will die. At this point the engine will not turn over at all, all lights function. I can come back in a half hour or so and it will start and run like normal.

 

Any ideas?

sounds like the battery voltage is falling below threshold.

 

could be a loose alt belt

 

could be corrosion on any of the battery connection points.

 

Best thing to do is beg borrow or buy a voltmeter

 

Easy way is to put it on a cig lighter plug.

(center pin is positive)

 

Plug it in and watch the voltage while idling

 

Normal charge voltage at ~1500 RPM = 13.8 -14.2 Vdc

 

Hope this helps.

I would check the fusible links for a loose connection problem. It may also be an intermitant relay or a bad connection somewhere.