No1 Fuse Blowing

[lilblue1970]

I've just about tried everything to cure this, so as a diagnostic test, I took out all the relevant components associated with fuse 1, sidelights, right rear lamp and number plate light. Took all the bulbs out and pulled the dash light switch one click and 'ffzzzzt' the bloody fuse goes again. I've checked all the wiring and renewed where it looked at all dodgy and cleaned everything. Anybody any clues? It's a '70 Bay by the way.

 

[lilblue1970]

Anybody any ideas where to look first?

 

[froggy]

Do you have a multi-meter?
if so then follow the wire from the fuse box to each component and test for continuity to earth,
If not then stock up on fuses and do it the old fashioned way, remove all the bulbs and starting at the closest component fit a bulb and try if the fuse blows then the problem is between here and whatever is before it in the circuit.
No easy way to fault find an electrical fault without a meter really though, even a cheap £10 meter is a gods send

 

[aogrady]

Hi.

My windscreen wipers used to blow the fuse when i turned them off, they worked fine when running - till you turned them off?! I changed the switch, and they have been fiune ever since.

Maybe a new switch may help, would always help to have a spare even if this doesn't fix the fault.

Good luck in the search

Alistair

 

[lilblue1970]

Cheers for the pointers guys. Think I'll be investing in a multimeter.

 

[Araon]

its not uncommon for the switch to spin and short the terminals to the dash.....also years of fluff and general shite in the switch.....

note the connections and remove the switch give it a good clean, you'll see the potentiometer windings for the dash iluminations and you should be able to gauge wether its generally fucked from the condition of the windings

 

[ray]

Have you disconected the wire going to the back of the dash black wire from fuse one it feeds the fuel gauge ect the card spacers to the fuel gauge on mine broke up and the connector shorted out

 

[lilblue1970]

Thanks for all the ideas on where to look. Just need a decent break between the rainclouds to make a stab at it.
On the subject of dash switch removal, how is it removed? Is it a circlip or something? I can't see any obvious way to remove it. Haynes and Bentley aren't much help on the subject.

 

[Araon]

unscrew the knob

then unscrew the silver bezel (with the two notches)

withdraw

 

[merlin68]

worth checking condition of fuse holder itself as sometimes excess heat from shorting can melt insulating plastic around fuse clips quick way to check is blade fuse of correct rating connected to in anfd out wires on fuse box

 

[jonboylaw]

What tool do folks use to undo the switch ferrule ?

 

[Mickey Sam]

There is a proper tool you can buy for this. Can't remember who sells them but am sure it's one of the usual suspects.

I used two small screwdrivers but it's not advisable as its too easy to slip and scratch your dash !

 

[Trikky2]

See my reply to your other post.

By the way - you dont need a multi meter - you can do all the testing you need on the lighting circuit using a test light - like those screwdriver ones with the little wire and crock clip they sell at halfords etc.

If you connect your crock clip to a live feed then you bulb will light whenever you touch the blade to an earth. You can now test each wire and connection to see where the short to earth is.

 

[jonboylaw]

There is a proper tool you can buy for this. Can't remember who sells them but am sure it's one of the usual suspects.

I used two small screwdrivers but it's not advisable as its too easy to slip and scratch your dash !

I used a small pair of pointy nosed pliers in the end, worked a treat.

 

[Trikky2]

I used a small pair of pointy nosed pliers in the end, worked a treat.

Good point - I had completely forgotten thats how I did it last time :lol: