Dim headlights problem

[seaandmoor]

I've always known that my +2 headlights were very poor.
I have tried swapping the lights and bulbs for much brighter ones from another car but they also glow dimly in the +2 - and so do the fog lights under the bumper.
Battery is good, charging is good, not sure where a poor earth might be and I haven't run a wire from the battery directly to the headlight earth but suspect it wouldn't tell me anything.
Before I start trying anything else that proves a fruitless waste of precious time, can anyone point me in the right direction to get some brightness up front please?
Thanks in advance.

[JohnMorin]

Definitely check the earth's. The next suspect would be the relays.

[gherlt]

I would also clean both contacts of the bullet connectors in the front area, a lot of water and dirt coming in there.

[Andy8421]

Rather than a scatter gun approach, the guaranteed solution is to treat yourself to a cheapo multimeter (if you don't already have one). They cost virtually nothing these days from Amazon or eBay.

Attach one lead of the multimeter via a long wire to the earth terminal of the battery as a known good earth, and work your way through the headlamp circuit from connector to connector with the other lead of the multimeter (set to DC volts) with the headlamps on, and see where you are losing volts. You will probably find a number of connections that are flaky and all contributing to the problem.

You should also check the earth connections with the meter. Any significant voltage at the earth at the headlight bulbs indicates a poor earth that needs to be tracked down in the same way.

[seaandmoor]

Thank you for the advice. I don't have a multimeter but should have had one years ago. Time to get one!

Since discovered that the headlight bowls are really very rusty and the grommets that the beam adjustment screws go into have crumbled away so I will need to order complete new bowls and trim rings. Are these bowls and trim rings commonly available cheaply from somewhere rather than paying a small fortune from a Lotus dealership?
Thank you again.

[GLB]

I bought new headlight bowls from Moss motors here in US, I think they fit MGB but probably common to many British cars. Inexpensive too. No affiliation to Moss. Gary

[seaandmoor]

Cheers Gary, I'll give them a try in the morning.