You don't want to wait till the clicking to stop, as soon as your light goes out is when your plugs are the hottest.

 

usually if you can hear it clicking after the light goes out, that indicates some glow plugs have failed, and replacing the whole set is advised. with motorcraft plugs of course.
because its only 10 seconds of cranking, you don't appear to have a problem with air in the fuel, so get those plugs and it should be good to you.
if budget doesn't allow all new plugs, they're easy to test (mentioned in many threads here, i won't go through it again)

 

The 85 model will click several times even after the motor has started, that is how they were designed.

 

The clicking you hear is the gp's cycling on and off. Their st their hottest (easiest to start) when they light goes out before they click. When they stop clicking they arent on.

 

awesome guys thanks for the info.

 

What?? The clicking is the normal cycling of the glowplug cycle. It has nothing to do with whether the plugs are good or not. That clicking is to help the cylinder heat up faster with a cold engine, and ideally is happening right after it starts.

In the newer glow plug system, a short wait to start light time (under 10 seconds), MAY be an indicator of faulty plug(s), but by no means is it conclusive either.

I will agree that when replacing plugs, the motorcraft/beru plugs are the best recommendation, and if/when possible, I would also suggest replacing them as a complete set.

 

my mistake, i was thinking it functioned just like my 87 does. in the 87, you don't hear it clicking on and off when all plugs are working, apparently that was a change for the later style the 87 has.