glow plugs d236/282

The (+) lead gets hooked to the battery, and you touch the (-) lead to the glow plugs (with supply wire unhooked from glowplug) one at a time to see how much they draw.

Once you know what is normal for your unit, you can then compare the draw of each plug. Most of the time, they are all pretty close, or burned out (and draw nothing), but there is the occasional plug that will still work, but draws way less than it should.

On the Ford or GM diesels, typically each plug will draw 10 or 15 Amps. A year ago I checked out a 706 with the ammeter, but I don't recall what amperage those drew.

The easiest way is to hook a test light to positive battery voltage and test them one at a time with all the leads disconnected. If the test light 'lights', they are generally okay.

Allan