Glow Plug TEST QUESTION
Having a hard time getting truck started in mornings. I live in North Texas, so it hasn't been extremely cold, upper 30's-mid 50s is when I'm having problems. It pours white smoke while cranking and is rough idling for a few minutes till it warms up a little, then runs/starts great for the rest of the day. It's a late 99 with 215,000 miles. Have only had it for about 3 months, so I have no idea how old the glow plugs are. I have tested the glow plug relay and the harness where it attaches to valve cover with multimeter, and both are good. I tried to test the glow plugs by checking resistance on the 4 pins of each valve cover electical connector, and got no reading at all. I tried the test light method of attaching one end to positive battery terminal and touching all of the glow plug connections on valve cover harness, and got no light on any of them. I wouldn't think it would be possible for them all to be bad. Any ideas on what I am doing wrong, or can they all be bad?