On Thursday morning I gave up trying to start my '84 Burb. 3rd cycle of the glow-plugs, 3rd time cranking, a solid 8*C outside. Better stop now before I wreck something. Today I attacked the glow plugs. Its a good thing you can make an AC clamp-on meter work on DC if you do it right (set it for peak value, and cycle the solenoid once or twice.) So I tested the first two glow plugs. They drew ~10-15 amps each. Then I thought I'm check the total draw at the solenoid.... 28 amps I put on my rocket-scientist hat and deduced that not too many other glow plugs seem to be working. So I started taking them out... hmmm... the are marked '11G'. I guess they're all coming out then. Surprisingly, they all came out easily. None were mis-shapen or distorted at all. They had some carbon on them, but nothing a little back & forth turning couldn't break loose. The two good ones came out extra easily - and the ends were clean. (a good tip if you didn't/can't check electrically before you dive in). Then I checked each glow plug connector for voltage as I cycled the solenoid. All okay there. I had bought my 60Gs many months ago... (back when I replaced the batteries and starter ). After installing them, I noticed many of the wire connectors were loose - loose enough that electrical continuity was suspect. Used a small screwdriver to pop the back plastic sleeve off the connector. Gave the connector a slight squish with pliers, and put it back together. Much better. Got out the ammeter again to check the NEW current draw at the solenoid..... 92 amps this time. 5 seconds on my glow-plug button and it fired right up.