2 Problems... Horn & Dash Lights (MOT pending)

[davidvincent]

(1980 2ltr Petrol RHD CU)

Hi all,

I have done my searches and checked the wiki but still not resolved my two probs, all advice is welcomed as my MOT is booked in for next Monday.

My previously intermittent horn is now silent, here's what i have checked:

- Removed horn and ran straight from the battery - it worked.
- Checked continuity between earth strap at battery and at the steering column/wheel spigot - earth was there.
- Checked that the spade connector at foot of column was well attached.
- Looked for voltage at the horn but got only a very low reading, like 0.06.
- Looked for voltage at steering wheel but got nothing, I gather this is correct as is only an earth switch?
- Checked the actual push button itself - no probs.
- Checked fuses - nothing blown - I guess the horn is fused? The brown blue wire from the wheel runs over towards the fuse box area but then heads elsewhere, so not sure about this - could there be an in-line fuse?

My other problem is that my dash lights do not work when the headlights are in use, I assume this will be an MOT failure as its tricky to know your speed at night.

A few things....

- This problem went away for about 6 months and has returned.
- I have checked the earths by the fuse box and all seem good.
- The dash lights do turn on when I stop the engine, that is if I leave the headlights on before switching the ignition/engine off. This rules out the bulbs.

Again, any advice appreciated....

David
SE London

[Damien]

Should pick up voltage at steering wheel, needs to be a good 12v ish. Check for voltage at fuse box terminal, if you have it there then theres probably a problem with wire somewhere.

Dash lights sound like a problem with the circuit board on back of speedo.

[davidvincent]

Should pick up voltage at steering wheel, needs to be a good 12v ish. Check for voltage at fuse box terminal, if you have it there then theres probably a problem with wire somewhere.
.

Hi Damien, and thanks. So when u say I should get a voltage at the wheel, should I get it at the brass pin that the wheels runs over? Or at the wire in the clip on the left with live/red wire?

[fullsunian]

You only need to sort the horn for the MOT matey

[mirams]

Could be an earth problem for the dash rights, check the ring connector behind the fusebox, some of the spade connectors may be dirty.

[davidvincent]

You only need to sort the horn for the MOT matey

Oh great, that takes the pressure off a bit then....

Could be an earth problem for the dash lights, check the ring connector behind the fusebox, some of the spade connectors may be dirty.

Ok, I have checked those out before but will give each one a thorough 'wire wooling'

Thanks all,

[davidvincent]

Hi All,

Update... the horn lives again! After re-soldering the brass clip/runner beneath the wheel it now has a really strong connection and works well.

Also the dash lights are fixed! I spent some time cleaning all the earths on the circular brass bit but had no joy, then traced the earth from the dash only to find that a newer wire had been installed and had been 'earthed' badly elsewhere, i rerouted this to the brass terminal and all is well again

Now I just need a new wiper relay and im all set

Happy days, thanks folks.
Dave