I've heard of water in the GP relay eroding the traces on the circuit board -- it is possible that the light circuit is bad and the main timer circuit is still working.

Take a look again a the inards of the relay, checking that the traces on the board are all still there. If one is missing or broken, you can repair it with solder or a small bit of copper wire and solder.

The click is the relay opening (will also click when you turn on the key) -- if it starts, the glow plugs are working, just the dash light is not. You can check for voltage at the glow plugs with a multimeter, and also the resistance at the plugs (take the six wire plug off the relay to check resistance).

It is also possible that the resistors in the relay for each of the glowplugs are bad, too, in which case not all the plugs will be drawing current and the dash light won't work.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!