Hello lamby. You need a digital multi meter with a milli volt scale (cheap is fine)......Attach the positive lead to the bolt head on the glow plug bar where the large wire coming from the glow plug relays attach and the negative to the Block....not the battery ground...............extend the leads with jumpers so you can have the meter inside the cab to a place that you can safely see while driving.........

I am not going to tell you what the readings should be at this point, all I want you to do is see that the readings are very responsive to your driving conditions...............

Make notes of the readings when at the following conditions:

30 seconds after you start the engine and at idle rpm....

go for a drive (about 10 miles) and note the highest reading you get ...............

during your drive find a stretch of highway that is very flat and note the reading at 45 MPH while in fourth gear.........

play with it.......see how the readings change with rpm, going up a hill and down a hill or when you see smoke from the tail pipe........notice any relationships to the readings and driving conditions.........

when you return home, note the reading at idle........

I need to know what fuel you are using during the test and if the engine is turbo...........

feel free to call me if you have a question, but I want you then to post on open forum what your question was and my reply........<img src="/forums/images/graemlins/patriot.gif" alt="" />

regards,
crossbones
919 698 6613