Series 3 Dim Headlights

I'm nearing completion of restoring my old Landy but I have an electrical fault which I think is caused by a combination of old wiring and poor earthing. The symptoms are dim headlights, both bulbs just about glow orange when on dipped or main beam? I have cleaned up the earth point under the bonnect catch which is where the earth for the lights connect to ground and have replaced both bulbs. I have already replaced the the stalk switch due to a problem with the indicators. Therefore I think the cause of this is a bad earth where the power is being lost due to a high impedence in the ground or wire feeding the lights, has anyone else had this problem?

I'm gonna try connecting a jump lead between the battery negative terminal and the earth point to see if this makes any difference before rewiring them, also when the engine is running makes no difference to the brightness. I'm confident that the battery is charged but havent yet tested this as the engine turns over O.K which requires more grunt than running just the headlights!!

Look forward to your words of wisdom???? Regards.

Check voltage at bulb end and at switch end will give you some idea where abouts in the wiring the fault lie.....measure volts against the nearest earth so as to get a true reading.

O.K found out the problem was with a duff earth from the bulb to the inner front wing, replaced this with some nice new wire and the lights work fine now. Tried just cleaning the contacts but this didnt make any difference, as the impedence on the wire was to high. When stripping back the wire it was black instead of copper. Hence the need to replace.