If one has replaced the radio suppression relay in one's 740 last year, and one tries to start one's car at lunch today, and it starts fine, runs for 30 seconds before one turns on the radio, when it immediately stops running, does it sounds suspiciously like one got a bad radio suppression relay, or could it be another electrical gremlin also directly affected by the radio? The reaction was too close to be coincidence - the radio must've done it somehow.

I had it towed into a shop when this first happened, and it naturally started and ran just fine by the time they got it in there for testing. The radio suppression relay was first in a line of two or three other components that would shut the electricals off during an attempted startup. I replaced it myself. Seemed to be work kind of spotty at first, until I had it seated correctly. Worked fine until 1 week ago, when I had a similar incident.

I don't hear any fuel pump action going on when the trouble hits, as I do just before a normal start. Fuses are fine.

Suggestions, anyone? Thanks in advance.