After a 4 week vacation this summer, I came back to find the 240SE a no start, and traced it to the FP/system relay. It was not closing.
Seemed to be voltage present so I pulled the relay and found the coil winding open.
Replaced with good used relay, car starts and runs.
Then watching the relay, I noticed it was not opening when the ignition was turned off. This coil + gets voltage all the time directly from the battery, and is turned on through grounding the coil- in the ECU.
After waiting awhile, the relay would disengage, but sometimes seeemed to be always on.
First thought was, no wonder the coil failed. it was in the 90's many days (I was not around, thank goodness) and the car in the sun, it must have gotten very hot under the dash, and with the current running through it constantly, it burned out.

I have a voltmeter on the coil -. The car usually starts fine, not always, today it did not, and I manually pushed the contact closed, it held and the car was fine.
When turning off, the coil stays on (and the voltage at about 1.2 volts) for about 2-3 minutes, then the voltage goes to 12.6 and the contact opens.

So, I don't know what to make of this. Is this normal? It almost seems as though the coil needs a pull up resistor to bleed off some capacitive charge.

Ideas welcome>>
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245 Classic M47, 245SE AW IPD bars, 84 1/2 242 Tic IPDbars & Springs, 89 745 16v M46, IPD bars, 89 744 16v M46 IPDbars