Floydo,

The system is telling you that you have an open glow plug (GP) as it is designed to do. Using an ohmmeter, measure the resistance of each GP and replace the one that is bad.

Measuring is done easiest by removing the cable connector from the GP relay and measuring in the connector holes with the other lead of the ohmmeter connected to a good ground. A "banana" plug works perfectly in the connector holes. You should read about 0.7 ohms on the good plugs and higher or open on the bad plug.

Don't let anyone talk you into replacing all the GP. You only need to replace the bad one. All you will need is 8mm and 13mm combination wrenches.

P E H