Greetings everyone, first time poster here but long time Benz owner.

My neighbor has a 1996 E320 sedan that he has asked for some help with. It seems it has been intermittently and suddenly dieing while driving. No stumbling to a stall, just suddenly no more engine. Attempting to restart the engine would be met with starter but no fire. Then after allowing things to set for a while it would restart. First thing I thought was K40 and CPS. I started at the K40 as it is the easiest to access. First impression is the 40 amp fuse in the F4 position is blown. I opened up the K40 and there is no sign of damaged solder points. I replaced the 40 amp as a long shot and it proceeded to burn it out with in a min of the engine running.

Can anyone tell me if they feel if the K40 is bad it would burn out said fuse, or is it more likely something else upstream, deeper in the electronics is burning it out? Interesting note, the car will start and run with this fuse popped, not sure how long, but I was surprised by this.

Thanks for any and all assistance.