Fuse number 18 pain in the butt

Keeps popping and I dont understand why, all I can think is a bad earth on the steering column but I wire brushed the rack terminal and put new screws on as they were rusty.

I believe it's for the horn and coolent temperature ( probably wrong like )

I tried a larger 30 fuse instead of the standard 15 in case it was bodged to power other things but it still popped

Oh its a 1986 golf gti 1.8 8v cabriolet

fuse 18 is for the horn and coolant level control relay.

start with the relay pop it out and check for corrosion in the socket. look at the wires out the back too follow the black or black/yellow wire back to fusebox. if all looks good check the horn wires next, unplug them then follow the wiring back as far as you can. if that all looks good leave relay and horns unplugged, then swap the fuse over. switch ign on, if fuse blows again you have wiring or fusebox issue, if not then its either the horns or the coolant control relay. plug them in 1 at a time and try again, see which one blows the fuse.

check the wiring to the horn relay as well, there should be a jumper wire from L 1 to A25. see the fusebox sticky

Thanx your ace

I'll do my best to follow that eek! Electrics are not my strong point

If its my fuse box will a carb model one work?

any post 83 mk1, cabby and scirocco will do, plus pre-90 mk2 golf regardless of engine

Ok so I did what you said and turns out it was the fuse box

Thank you

I do have a new problem I didn't notice before the fog lights wont work and the reverse lights are on continuous

pull the wires off the reverse switch on the gearbox, see if that stops them. for fog lights does the little warning light come on the 2nd click? check the fuse above the fusebox, thats for rear fogs it'll have grey/white wires out the back. check grey/white wires to the rear bulb holders and check the actual bulb and the socket it fits into are ok. they can get corrosion on the contacts

I pulled the connector off the switch for the reverse light on the gearbox and it remains on. I disconnected the engine bay wiring loom and it remains on, only goes off when I remove the connector for the rear loom.

The fog light does not receive any power with 2nd click and fuse is ok and all connectors are clean and tidy. Could it be the headlight switch? I know it only comes on when the headlights are switched on.

ok sounds liek something isnt wired up properly or this new fusebox is messed up as well!  the engine loom if disconnected rules out any wiring issues up front, so that just leaves the fusebox or the rear wiring loom. have you definitely got the rear wires on the clusters right?

disconnect the brake pedal switch wiring, see if reverse lights go out then. there should be a 2 pin plug near the fusebox with a red/yellow and red/black wire, this is where the brake light switch loom joins the fusebox, the plug hangs off the yellow plug for the lighting loom fyi.

for the fogs, follow the wires from the fog light switch back to where they come from. there should be a grey/yellow wire back to the fusebox this is the power input, it should be live when the lights are on. not sure if its on with sides or only dip/main on a CE1 fusebox, so check both. then trace the grey/white that should run direct to the fuse holder, then the other grey/white from fuse holder goes to the fusebox B/2. then the rear wire runs from E/10. with the fogs switched on check for power at all the above points to see how far power actually gets