RE: afterrun thermoswitch BTDT

[Phil and Judy Rose <pjrose@servtech.com>]

Henry,

Just a thought: If the "test" was with the hood _up_, that may have gotten
the system cooling off too quickly for the after-run to get switched on. I
think the after-run may be designed to work only in pretty extreme
heat-load situations. If so, and if the difference between 60F and 70F
(outside temp) is significant, then having the hood open is probably gonna
be significant as well. (damn I don't wanna have to replace my switch!!!) :(

Phil

>Phil R. sed:
>> When I replaced the multifunction switch on my '89 100, I was able to get
>> the new one in before more than 1/4 liter (or so) of coolant had escaped.
>> However access to the after-run switch on the '91 200q is _so_ limited that
>> I'd expect to lose a _lot_ of coolant.
>>
>> Let us know if you manage the job without serioiusly skinning at least 3 or
>> 4 knuckles. I got some painful abrasions just getting the connections off
>> to do the test. :(
>>
>
>Contortions definitely required. I let it cool off *almost* enough to not
>burn
>myself on the various warm things around there, and the
>oil-level-checking-device tube is very much in the way.
>
>> BTW, on my "new" '91 200q, the after-run came on for the first time about
>> 10 days ago when there was a spate of unseasonably warm weather (close to
>> 70 F, wow!). I idled the engine in the driveway until the cooling fan came
>> on and then shut the engine down immediately (temp gauge at 12 o'clock.)
>> Then I checked the mail, went inside the garage, started around into the
>> house, and after what _must_ have been at least 4 or 5 minutes, the
>> after-run came on. This was a very similar experience to what I encountered
>> with my previous car--although it was during the Fall season then.
>>
>> So, although it may still indicate a faulty component, it's possible that
>> the after-run sensor might not trigger without warm outside temps plus
>> having several minutes to activate--when we're likely to be long gone.
>>
>
>That's more like a BTDT that I asked the list for earlier, but was probably
>buried in an unrelated note.
>
>Here's what I did yesterday coming home from work. Well, I drove home,
>about 15
>minutes, temp gauge is at first bold hash as usual. Ambient about 70F, but
>becoming partly cloudy and cooler. Let it sit idling in the driveway,
>(hood up)
>trying to get fan to come on. With AC, stage one fan is always on, at idle
>for
>this temperature not enough heat generated to get stage two. Turn AC off, get
>stage two (from stage zero) every five minutes for about a minute. Get bored,
>leaving hood up, turn off engine and begin to play with my favorite driver's
>door innards while things cool off so I can pull off the afterrun switch
>connectors to test the pump. I mess with the door for 20 minutes or so before
>connecting a particular way to reassemble the inner handle with that silly
>clicking noise when lock/unlocking, don't ever hear the fan/pump come on.
>Hood
>is still up, of course, so I do the short-connectors-together test to verify
>pump can run. It does, I put them back on, ponder a bit, then go fire off
>note
>to q-list.
>
>Perhaps the system is still functioning as intended, and I just haven't
>got the
>car hot enough and watched it afterwards. The cooling system does seem to
>have
>significant ability, so the funny thing is that running the car hard and then
>shutting it down to check afterrun workings seems to border on vehicular
>abuse
>(if the afterrun doesn't in fact work after all).
>
>No luck on any such test today though, it's now under 50F and raining to beat
>the band. Good quattro weather, anyway.
>
>Hmmm,
>Henry Harper
>http://www.srv.net/~hah
>1991 200 quattro, 87k, does or does not the afterrun subsystem work properly,
>that is a question for another day
>1988 GTI 16v, 177k, only rarely do I hear the afterrun fan come on in this
>car
>(and pretty much never hear the turbo pump :)


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