1800: How can I check horns

[p1800]

Hi Guys
Ive now got no horns working at all!

Ive had the car for 15 years and always has the horn on the stalk working. The push on the steering has never worked.

The stalk has just failed - I hear a faint sound as if a current is making a diaphragm twitch ( almost a pop noise ) when the stalk is pressed

There are 3 horns in the nose - a single and a pair - which one works off the stalk and which off the steering column.

How can I check if it is the wiring or the horn ? There are 2 spade connectors to each horn - can I power these up directly to see if they work and how would this need connecting? Is it standard earth through the body - if so why are there 2 spade connectors to each ?

From reading up on this I believe the steering column horn push completes an earth circuit - how can I test if the wiring is working before spending £80 on a horn set?

Any help appreciated
Thanks

[Derek UK]

You should have a horn relay, a smallish rectangular one. Check and clean the wires and connectors. You can also check the horns individually with a jumper wire from your battery or a spare one. Earth is to the fixing bolt which is probably fine so a single wire from the positive of the battery to the horn tag should wake it up, or not. Clean up all the contacts anyway. The horn button in the centre of the wheel can be fixed, parts are available for little money and bit of patience.

[p1800]

Thanks Derek
Is the single horn wired up to the stalk - and the pair of horns operated by the steering wheel push ?
Mike

[Derek UK]

Originally Posted by p1800

Thanks Derek
Is the single horn wired up to the stalk - and the pair of horns operated by the steering wheel push ?
Mike

Some 1800 models have two horn pushes which I think they use for town and country horns. If you have a handbook that will probably explain. A comment from other 1800 owners needed here.

[Ron Kwas]

P;

I cant answer your questions with certainty, but I am following this thread and will compile info into the Horns Notes compilation here: http://www.sw-em.com/122_horn_notes.htm

Typical P1800 Wiring Diagram like here: http://www.sw-em.com/1800%20Wiring%20Diagram.jpg ...does not show a relay, but there were variations from the factory, such as your dual Horns arrangement...as well as changes by POs...so one needs to do some careful investigating to determine which arrangement one truly has...then troubleshooting can follow...

The "pop" noise is actually a good sign...in that it rather confirms that switch is working and that power is being applied to something (either a Relay or Horns themselves)..confirming source of pop will be a good start to troubleshooting! Horns can indeed be checked by disconnecting them from normal wiring, and directly connecting them to Battery power...observe polarity!

Horns are actually a close cousin to relays! They are in fact also a coil on an iron core, set to pull in a moving armature...but the contact which the armature controls is in series with its own coil...so the whole thing self-vibrates as shown in the article...but if the critical characteristics change, due to contact wear or corrosion of the moving parts... it might not work...non-working Horns (once confirmed) can certainly be replaced, but there's little satisfaction of curiosity in that...drill rivets to open, its often possible to repair them and bring back function...! Remember also that Horns are a pretty significant electrical load...this means good high current connections for the entire current path are required!

Good Hunting!

[arcturus]

Originally Posted by Derek UK

You should have a horn relay, a smallish rectangular one. Check and clean the wires and connectors. You can also check the horns individually with a jumper wire from your battery or a spare one. Earth is to the fixing bolt which is probably fine so a single wire from the positive of the battery to the horn tag should wake it up, or not. Clean up all the contacts anyway. The horn button in the centre of the wheel can be fixed, parts are available for little money and bit of patience.

The fixing bolts corrode and cause bad earth. Make sure clean and rust free to chassis. been there, had that!

[p1800]

Thanks, I'll check the earth

If I do that and want to test if the horn is working - There are 2 spade connectors on each horn - which one should i put power to to test it ? ?

[arcturus]

Originally Posted by p1800

Thanks, I'll check the earth

If I do that and want to test if the horn is working - There are 2 spade connectors on each horn - which one should i put power to to test it ? ?

Makes no difference.

[Ron Kwas]

P;

If two Terminals are present, both connections to the internal circuit are brought out and accessible, so there is no polarity preference*.

If Horn has only one Terminal, lowside is internally connected to chassis, so this polarity must be observed.

*BUT...for the purposes of troubleshooting, I'd trace back wires from terminals, either by color code or by seeing which one actually goes to chassis, and duplicate this polarity arrangement during test. (...because polarity on actuating coil determines direction of armature movement, and with a sluggish armature, this might be significant!)

Remember also that a poor connection ANYWHERE in the current path can cause voltage drops and functional issues.

Good Hunting!