Headlights (and dashboard lights) very dim

[michaelkaye]

So I drove my sport for the first time in the dark the other day and got to say the headlights were incredibly dim.

Plus I my instrument panel was barely lit up (even with the rheostat turned up).

Is this normal or an indicator of problems with the electrics? If the latter, any hints as to where I should start.

I’ve checked the fuse box and there doesn’t seem to be any corrosion. Could it be the relays (no idea where they are to be honest). Poor earth? But where?

Thanks, Michael.

[davidwheeler]

Problem with electrics.     Dash lights are fairly dim anyway but rheostat likely grotty and passing little current.   I run 100/80 watt QI headlight bulbs which certainly helps but would not do if the earth were poor which is your most likely problem.   Fuse box tends to poor contact as well especially the wires going in and out so it would be worth checking the state of the wires and tightening the terminal screws.   Corrosion inside the terminal posts can be difficult to see.   Relays are those metal boxes behind the fuses and either they work or they do not so the problem does not lie there nor in the column switches.    I have run new earth wires from the headlights to the body shell to which they are fixed with self tapping screws.   You could also check the voltage going to the headlights bulbs - a test meter costs only a few quid in Machine Mart.    Should be 14 volts or slightly more with the engine running (theoretically 14.7)

[michaelkaye]

David, thank you for the comprehensive reply! Much appreciated. M.

[frankxhv773t]

Remember also the thread earlier this year about using the normal headlight current to power a relay and running a new circuit from the battery to the lights via the new relay.

[michaelkaye]

Thanks I’ve not seen that thread. I’ll have a look for it.

[nistri]

Clean to bright metal the earth connection from the (-) pole of the battery on the gearbox, Andrea

[michaelkaye]

Finally got round to looking at the headlights. Checked fuses, relays etc and all looked good. The connectors to the lamps themselves weren't in great condition but nothing that would explain the dimness of the lights when on dipped beam.

I tried running a connection from the battery directly to the lights just to test, and they were still incredibly dim.

And then I noticed that on dipped beams, both filaments of the bulb where coming on. Very strange. Had a look at connector plugs and became convinced that the cables where the wrong way round and the fact both filaments were coming on was the cause of the dimness. Prized the cable connectors out of the plugs and swapped them over and still the dim! Very strange.

And then the eureka moment; the plugs themselves were in the wrong way up from the beginning. I, and obviously whoever connected them up in the past, didn't think this possible, but yet if was. Rotated both plugs 180 degrees, connected to the headlights and brightness has returned to my Fulvia!

I thought I would mention it just in case anyone in the future experiences the same issue!

[michaelkaye]

One question I do have though. How are the relays (solenoids) earthed? I could not see any earth cable running to them anywhere!

[Richard Fridd]

One question I do have though. How are the relays (solenoids) earthed? I could not see any earth cable running to them anywhere!

.         Via the relay casing?

[michaelkaye]

Thanks for the reply.

Via the relay casing?

     
That's what I thought but the relays are mounted (along with the fuse box) directly onto the plastic panel (which hinges down) so I can't see how they can be grounded.