[piscator]

Good Morning Gentlemen,

Greetings Pat!

I’m sure you’re right that it’s the air-flow switch. I’m learning a lot about this stuff! The link Pmax offered is an excellent tutorial. So is film he posted.

Tony,

Thanks for your generous offer! Before I take you up on that, I’m going to re-do the control pressure tests today, just to double-check that I didn’t do something in error (always the first likelihood).

The Cold Control Pressure @ 18 psi and the Warm Control Pressure @ 31 just baffles me. I find it too strange that the WUR should fail while sitting in my shop, on the engine, idle, for 8 months. Any thoughts on that?

“911, 911S, 911SC (since 1976). By-passing the electric safety circuit. The electric circuit can be by-passed by disconnecting the air flow plug or by bridging terminals 30 and 87a with fused (8 amp) jumper wire.

No question! Your rewording is far better! Your version clears up the confusion as to what gets ‘bridged.’ That’s where I got stuck, thinking there might be another terminal 30 and 87z on some relay or component I didn’t know about.

WARNING: Abstruse pedagogy ahead, proceed at your own risk!

I suspected that the error might be in the translation to English, but it seemed odd that the translator would use the term bridging in three locations, if it hadn’t been phrased that way in the German.

Just to be pedantic about it, I turned to GoogleTranslate to find that the German for “bridging” is “Uberbruckung.” In German the word emphasizes ‘getting over’ or ‘getting around’ something. It appears to be synonymous with the English word “reconciliation.” Understood in that manner Uberbruckung seems to carry the connotation of your English word choice “by-passing.”

In English, the word “Bridging” certainly implies ‘getting over’ – but the stronger connotation, I think, is the sense of ‘connection.’ We use “bridge” to mean ‘connect one side to the other.’ The word’s connotation of ‘getting over’ seems a secondary meaning.

So the translator might have, correctly, chosen ‘bridge, bridging’ to represent “uberbruckung” – not knowing that, in English, it would lose it’s sense of ‘getting around’ or ‘getting over.’

What, to me, seems more egregious is the mislabeling of the components in the diagram. “R = Thermo-time Switch” and “D = Relay” are not terms requiring subtle translation. The German “Electrisches Relais” is correctly translated as “Electronic Relay” but it’s mislabeled component “D” when it should be component “R.”

If component “R” had been correctly labeled as “Electrisches Relais” in the original German document, it’s hard to imagine that the translator chose “Thermo-time switch” as the best English equivalent; simply by looking it up in his German/English dictionary! It’s more likely it was mislabeled in the original German document as “Thermo-Zeitschaltuhr.“

Isn‘t this fun?! Of course, it’s all conjecture on my part. I’m not a language scholar and I don’t speak German. If one our German speaking Pelicans finds himself bereft of absolutely anything more useful to do, maybe they’ll clarify some of this. ;-)

O.K. Time to go re-check the control pressures. I’ll report back later.

As always, thanks for the help!