The problem with these relays seems to be that they develop bad solder joints from all that vibration over the years, so don't be too surprised if yours starts to misbehave again.
I keep a jumper wire in the car to short sockets 7 and 8 as we discussed previously, just in case.
Now if you want a really troublesome part, try the tach sender in the 300SD - now that I have my 300SD back
, I am reminded that it is on its fourth sender at 195,000 miles. Time to take one apart and resolder it....
BTW, I tried the resoldering trick on my 560SEL fuel pump relay and had no luck.