The door switch is NOT for electrical safety. It is to shut the system down if the blower door falls off so Carbon Monoxide doesn't enter the air stream. Electrical safety is achieved by a positive means of disconnect at or adjacent to the furnace. The person or company that installed the furance with no means of disconnect has violated code.
Even if the door was removed and the switch was working properly it will still be live on one side of the switch. Just as if you took your panel off your breaker box and killed the main breaker, the main wires feeding the box are still hot.
Proper electrical grounding won't matter. If the HO got on a live wire and he was well grounded then yeah the jolt could have stopped his heart. We need to know if this was an upflow unit or if he was laying across it in an attic trying reach the backside to change the filter. Can you post the serial number too?
That paticular unit did not have chronic problems with the door switch however there were other issues with the heat exchanger and blower housing positioning in the GMP-075-3. I would bet that the door switch wasn't the problem in the first place. The symptoms you are giving us really don't add up.
P.S. I hope you are able to find out who sold the unit and if they had knowledge of an illegal act, such as not pulling a permit etc... We must get this stopped before more are killed. I will damn sure testify to that fact!
[Edited by Steve Wiggins on 01-05-2005 at 04:23 PM]