

| Subject: | Re: AFM test readings |
| From: | Neil N |
| Date: | Thu, 3 Jul 2014 10:47:43 -0700 |
You're welcome Harold. Of note, I found this comment from Tencent interesting: "On this particular AFM, moving the wiper hub at top did not show any problems, while moving the air vane did, so even slight pressure on the wiper hub can alter the pressure of the wiper on the track enough to mask a problem. " As a side note, if one decides to move the wiper board so wiper can contact fresh resistive track, beware. The screws holding it down are tight and can be a minor hassle should one strip at the head. BTDT. My coffee hasn't kicked in yet, so grey matter is still slow (er), and Tencent likely explained, but my guess is that since the AFM is supposed to operate off vehicle supplied ~ 5 Volts, supplying that to AFM while measuring voltage output of AFM, gives a more accurate indicator of resistive strip condition, wiper contact, etc. than using the VOM supplied voltage (lower?) to measure resistance. i.e. putting the resistive strip under ~ 5 Volt load creates a "real life" test. David or someone of that ilk (read: someone who knows way more than I), will likely clarify the "volts and ohms" behind this. ;) Neil. On 7/3/14, Harold Teer <teer.vanagon@gmail.com> wrote: > Neil, > > Thanks for alerting me to the video. Here is the link to the thread and > video. " > http://www.thesamba.com/vw/forum/viewtopic.php?t=369815&postdays=0&postorder=asc&highlight=tencentlife+afm+video&start=0 > " > > I had previously tested without power to the AFMs and noticed a linear > change in one and a jerky change in the other. From the video, it appears > I need power for the proper test and will try that later today. > -- Neil n Blog: tubaneil.blogspot.ca '88 Westy http://tinyurl.com/c8rlw6p '81 VanaJetta 2.0 "Jaco" http://tubaneil.googlepages.com/ Vanagon VAG *Gas* inline-VR Engine Swap Group: http://tinyurl.com/d7gd5ej
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