> Rick Knoble wrote: > Is it possible for glow plugs to ohm out okay and still be bad? > Perhaps shorted by carbon or something?
Yes. But a typical ohm meter is not very accurate at those ranges. Much better is to measure the current flow. I use an old-fashioned automotive ammeter. The ones that display -30,0,+30. I put 12AWG wire leads on it. To use it, I pop the top off of the glow relay and unplug the connector for the glow plugs. There is a contact for each glow plug in this connector, so I clip on meter lead to the fused side of the big, screw-in fuse and then touch each contact, one at a time. The socket has pin numbers molded into it, and these numbers correspond to the cylinder number. This method tests the supply 12V, the wire, and the plug. When cold, a good plug draws about 20A (Well, on my meter it point to the mark for 20 amps. I have not calibrated or tested the accuracy of that meter...) It will drop back to about 15A after 8-10 seconds. If the plug is bad, the current will be less. If the wire or connectors are in poor shape, the current will be less. If the supply voltage is low, the current will be less. -- Philip, who feels like he's repeating himself _______________________________________ 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
