Strange lighting fuse or am I going mad?

[Freebird]

I had a frustrating Sunday afternoon.

The nearside dipped headlight on the Vit has always aimed far too low. The MOT guy mentioned it last year and as it's getting darker, I thought I'd fix it.
As anticipated the two miniscule adjusters were totally siezed, so I took the light unit out to free them off on the bench.

When I put it back in, I inadvetantly connected the three spade connectors up wrong. They are separate on my car, not moulded together like a more modern setup. I assumed the middle one was earth - WRONG!

When I flicked the switch from side lights to dip, all the lights went off like a fuse had blown, but all the fuses in the fuse box were intact. The odd thing is that after faffing around for a quite a while with a multimeter under the dash, the power came back as if by magic.
I tried the lights again (before I realised my connection mistake) and, you've guessed it, the juice went west. I then checked and fixed the wiring fault, but still no joy.
Refering to the wiring diagram I saw an inline fuse in the wire from the light switch but couldn't find it anywhere. After faffing around again for a while the power came back, again as if by magic.

Could the in line fuse be a time delayed circuit breaker? Seems odd to me.

Boy I hate wiring!!!

Glen.

[ferny]

Have you damaged the column switch?

[Freebird]

No. Don't thing so. All is well now.

Glen.

[Richard B]

Sounds like some corrosion on a wiring contact; could be the fuse clips in the fuse box. The extra resistance is enough to stop the lights working.

[heraldcoupe]

Does your car have the original type dynamo charging system? Sounds like one of the regulator box relays has kicked out,
Cheers,
Bill.

[Freebird]

Hi all.

It's been converted to an alternator and the fuses and box are virtually new spade types.

There was definately 12v getting to the main switch on the dash, I even ran a tempoary secondary supply to make sure of this and bypassed the switch to eliminate this from the enquiry.
The power was interupted somewhere between the main switch and the lights themselves - possibly in the column switch, but why would this recify itself twice with no further problems?

Glen.

[ferny]

It contains moving parts. Maybe when it's moved in just the right way it works due to it being slightly loose or bad contacts. Silly things can happen, even if they appear to be correct and you haven't touched anything.

I went around for a week moaning how no-one moved when I was flashing them. Then found out the solder had come off of that connection.

[Pete Lewis]

The first place to look for a timed out connector is the bundle of snap connectors under the bonnet front edge clean em up well and add some vaseline after.
if you need some 3 way plastic terminal blocks go to your nearsest lucas factor
or anywhere else as they are still used today   Peter

[Freebird]

I finally traced the cause of this to the bullet connector between the dash switch and the column switch. It's a double one and the female part had broken up with age, resulting in high resistance I guess.

Thanks for all your help.

Sane (ish) again

Glen.