Either you are correct, and the glow plugs are indeed bad (I've one or two that read higher resistance than they should have been) or your meter needs calibrating. What does the meter read when you short the two probes together?
On the other hand, if you don't need all new glow plugs now, you will at some time in the future. Go ahead and get them, then decide whether to replace all of them, or one at a time as they fail. You can also verify your meter against a new plug (assuming the new plug is good). On Sun, Apr 1, 2012 at 8:24 PM, Hans Neureiter <diese...@gmail.com> wrote: > I use a Fluke MM. Setting it on auto or scale, same results. 95 O = 0.095 > KO, and it reads 0.01 Ohm. > > On second thought, the measurement of resistance may not be so > un-significant. > > I am pretty much aware of the laws of physics that rule our world, > including Ohm’s law. > > Cast in “Stone” they are; Gravity, Kinetic, Dynamic, Static, Electric, > etc., etc. > > A glow plug is a resistor, a electrical conductor with a designated > resistance. > > Current flowing through a conductor excites molecules/atoms and causes heat > - it glows and eventually burns up if current is not limited. > > Not knowing the metallurgical/chemical composition of a glow plug element, > it stands to reason to assume that the electrical characteristics > deteriorate, i.e. resistance increases. More resistance, less current, less > glowing. Ohms Law is irrefutable, nor is the fact that things deteriorate > with age and use. > > Ohm’s law is similar to the principals of Hydraulics: Pressure (V) - Head > (Ω) > - Flow (A). > > Only difference is that Head is influenced by Newton’s law (Static + > dynamic). Electricity is weightless and thus exempt from gravitational > influences. > > I just can’t get past the fact that Ohm tells me the plugs dont even get > warm. > > I am reading 95 Ohm instead of 0.9 Ohm. Kind of like 95 % dead. > > A Ohmmeter tells you just the same as an Ammeter knowing the Voltage. > > Makes sense of my experience. No pre glow fault indication, but the motor > was hard to start below 40 F. > > Well, #1 finally kicked the bucket and told me something is wrong. > > Just wondering if I am on the right track or way out in left field? > > -- > Hans Neureiter, Katy, TX > '82 300SD > '01 VW New Beetle 1.9L TDI > _______________________________________ > -- OK Don 2001 ML320 1992 300D 2.5T 1990 300D 2.5T 1997 Plymouth Grand Voyager _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
