Weird electrical issue

[Neilmk1gti]

HI fellas,

So i have trawled through countless pages but still cannot really find the correct info,

Here goes,

The car is a MK1 1982 GTI 1600 8V

Fusebox is the ceramic type, i have also tried another fuse box.

The issue I had originally was the horn sounded very weak when pressed by the horn pad, but it i worked the front washes/wipers the horn would sound louder and then if i turned the fan onto speed 3 the horn was the loudest.

I have checked relays, fuses and wires for powers and continuity.

I cleaned the earth point that's in the engine bay, rack to sub frame.

Where is the earth internally on the steering column? i cannot locate this.

Now the car also seems that it doesn't want to run, it will fire on one cylinder and die.

Ignition switch fault?

Thoughts and guidance appreciated.

[sports racer]

OK, go back to basics. The horn works by having a good +ve and -ve connection. Usually the -ve comes from being bolted to the bodywork but some horns have a permanent +ve connection and it's the earth lead to the horn button that triggers it. Either way the horn button turns it on.

Because it works better when something else is turned on means the original horn button isn't getting correct (full) power. If you've got a multimeter check the voltage at the horn button. Now do it with the fan turned on. If it's different follow the horn button wiring with the multimeter to find where the voltage loss is or rewire your horn button. If you haven't got a multimeter go out and buy one. They're cheap and a must have if you've got an old Golf. Check the earth lead too for voltage. Electrics are weird and you could be earthing through the wipers or fan.

Earth on the steering column is through the chassis where it's bolted to so the whole column is earthed.

Running on one cylinder and dying could be anything, even lack of petrol. Is the fuel pump making a sound? I suggest unplugging all the electrical connections in the engine bay and plugging them back in just in case you've got a bad connection. Do every connection, even the ones for the cooling system. You might need professional diagnosis on this one.

Cheers

Paul

[Neilmk1gti]

Thanks Paul,

The horn wires in the engine bay are good, 12v and a good earth (Has continuity to ground) So this tells me the wires from the horn to the fuse box are good. so i believe the fault is from the fuse box to the horn press.

I will keep trying to trace the fault

Thanks

[dubstar]

There is a number of earth point behind the dash/cluster. I would start there. It could be that, during a previous repair, someone left an earth unplugged or similar.

If that doesn't work, just sell the car to me.

[dubstar]

Also, just realized you are in Chelsea. Me too!! (I'm just beside the Edithvale rec park) Shoot me a message, it'd be good to come round and have a look/try and help you out

[Neilmk1gti]

There is a number of earth point behind the dash/cluster. I would start there. It could be that, during a previous repair, someone left an earth unplugged or similar.

If that doesn't work, just sell the car to me.

Id sooner the car sit in storage then sell it but good try

[roccodingo]

Check the fuse box / relay plate for water damage, ( may be able to see visible sighns of moisture or green corrosion ) the copper paths inside oxidise, increase resistance then cause all sorts of havoc.

[Neilmk1gti]

okay dokey, have an update,

the car now starts and runs and all functions work for 5 secs then when i work the wipers they are slow, then the fuse pops and then all the chaos happens when the wipers sound the horn ect.

Anyone else had anything similar?

[Vinda76]

Good news Neil, seems you have found the culprit (or at least part of it) . Is this with the wipers on or off the screen? Mk1 wipers have a reputation, and yours have been idle for years, so the linkage could be stiff causing the blown fuse.
Gav

[Neilmk1gti]

FIXED!

I re, re and re check the wiring and had to repair a failed fix.

It appears that someone has 'tried' to fix this fault before and pretty much put a power to a power and it was therefor short circuiting and blowing a fuse.