Quote:
Originally Posted by whunter
Originally Posted by funola
Unless your measurements were made with a piece of equipment called a milli ohm meter, they are probably inaccurate.
I don't see how this is possible.
To me the reading is only a reference.
The only test I consider valid is removal and glowing in a vice.
Accuracy 100%.
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A DVM is not designed to measure low resistance (i.e. anything less than 1 ohm) accurately. To do that, you need a milliohm meter that is pretty expensive and out of reach for most
Milliohmmeter - TestEquity
Milliohm meters use a 4 lead test probe in a bride configuration in order to get accurate low resistance measurements.
It's funny how people here argue whether the glow plug should be 0.5 or 0.6 or 0.7 or o.9 ohms when their DVM is not capable of measuring down to that accuracy.
A DVM is good to tell you whether a glow plug is open circuit i.e burned out or not, that's about it. If you find a glow plug with no reading (open circuit), replace that glow plug. Trying to measure the glow plug resistance with a DVM to see if it is within spec is not possible.
Pulling out all the glow plugs to test in a vise is a bit extreme IMO. Much easier to apply power to each glow plug while still in the engine with an ammeter in series so you can measure the actual current being consumed by that glow plug. It should start at around 18 to 20 amps and slowly drop to 10 amps as it heats up to it's final temp. If it does that, it is good. If not, it is NG.