diagram so that I can test the push button controller, the switchover valves (vacuum gates) and the various vacuum elements for an 87 190E 2.3?

I have been working on the heater core, it is in but now I am trying to sleuth with the push button unit which doesn't do anything to the system.

I have read where sometime solder joints go bad. Should I check any in particular?

I APRECIATE any help provided right now .... starting the second weekend of repairs ....................... ... .. .

Haasman

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'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)