if its a 660, all the lamps flashed on then off it's likely the ballast if one or two of the lamps flashed on, it's the wiring or lamps.If you have swapped ballasts and it lights up, you know it's the ballast. if you have an OHM meter or continuity checker there's a quick test that can be performed to trouble shoot a system run by an ice cap. this is for situations were some of the lamps flash on and off for a split second while other lamps do nothing. The lamps that flash are fine You need to check the other connections With a ice cap you need to power off and on again to check to see if it will work.Fixing it without powering off will not cause the lamps to light.Repeatedly turning it on and off quickly will cause a ballast failure so don't go crazy.
1.disconnect from the power source(unplug it)
2.pull the harness connector off the ballast.You don't need the ballast or AC electricity to do this test.
3.With the endcaps mounted and lamps in place,you can now test the entire system from the end of the harness(the male molex connector the part usually inside the ballast)
4. use the two probes as follows.
for each pair of colored wires used in your application you want to test for continuity.To do this you insert the probes into the exposed molex pins that are connected to the correct wires.Wires not used,like for a 660 unit 2 or 3 lamps are ignored(these wires should be caped off)
5.if you find you have continuity (the signal from one blue wire,for example, goes down the wire to the endcap to the lamp's pin across the filament back to the pin the endcap and to the blue wire and back to the connector)check the other pairs.If they all have continuity,the only other connections are the jumpers wires.Check those lamps at the end by going pin to pin on the same end of the lamp.
6. If it shows continuity on all connections your ballast needs to be fixed.i got this from icecap hope this helps.
