Full beam cuts out engine

Hello everybody.

This problem has only occured recently, and is an intermittent fault.

I've got a 1982 Mk1 Golf GTI. It fires up first time, but when I put the headlights onto full beam I can hear the alternator whining and it sometimes makes the engine splutter and eventually die. I can also hear the relays clicking about in the fuesbox, and all the electrics go off, including the digital display on the dash.

I turn the car off at the ignition, wait 30 seconds then fire it up again, give it some revs, and put the headlights on. This time it works fine. Next day, same fault, same solution.

I also tried using other parts of the car to test this: continually sounding the horn, and turning the heater on full had a similar effect.

It seems that by having the engine running and the headlights on full beam the alternator can't sustain the power outlay, as if too many things are drawing current??? Has anyone else had this problem?

I've checked the fusebox but everything seems okay, and I think the relay for the headlights is in the switch itself(?) which is a new item.

Any help would be appreciated!

Thanks in advance.

Forgot to mention there was no smoke/burning, but eventually it did blow fuse number 11, (in a early type blade fuse box).

Maybe a faulty alternator.  Have you checked the voltage, condition of the wires and connections?

Hmm, I thought faulty alternator may be the cause of it too - especially in this weather! The connections and wires looked okay, I soaked them in WD40 to help drive out any moisture.

I'll check the voltage tomorrow: it does appear to be a main power feed problem, as it's affecting the whole system, so the alternator would appear to be the culprit.

I can't see it being relay/switch/fuse based as it's not a localised problem, it affects the whole system - unless anyone knows different?

It has now started cutting out whilst driving, but soon gets going again. It also had a 'fit' when I was on dipped beam and using the indicators.

It doesn't have any problems in daylight, i.e. when the headlights are off and there's little drain on the electrical system.

I'll keep you updated, thanks for the help!

For a while , all of a sudden , mine used to cut out if I put on the lights too . Traced it back to a bad earth behaind the fusebox .

UPDATE!

Broke down outside Tesco's in Kenilworth. Called the AA to fix.

Unfortunately it was eventually found to be the main live feed into the back of the fusebox, this had somehow shorted out and burnt (was all black and melted).

Not good news.

Car will be off road until fixed, probably until the summer.  :cry: