My '97 E300D (131K) is having an intermitant No crank situation. The dash lights come on but not always the same ones. Sometimes its just the lower ones and on subsequent turns of the key, the yellow ! will come on and the reserve fuel light. When it does start, the ETS code on the screen can be reset. It has said Display defective as well but it clears too. What does Display Defective Mean?

Every few tries there is a slight clicking sound like it could possibly be the starter solenoid.

I have: R&R battery for testing-Good
R&R the starter for testing-spun right up, tested Good
Removed the K40 and soldered 4 hairline cracks, car started and ran fine for 2 days, now won't.

Questions: Does anyone think a new K40 could solve the problem? What do you make of the starter solenoid sounding like it is trying to kick in once in awhile? The headlights stay strong when the ignition is turned to start but the A/C blower motor drags way down.

Would be VERY grateful for some help...
MB Paba