Horn?

[ChrisPap]

Hi Guys,

I'm pushing on with rebuilding my car but can't sort the horn.

On a T350, I'm thinking that the horns mount to the same AV bobbins as the radiator? One each side?

And should the wiring for them be one black and one purple wire?

I can't see any other logical wiring for them but I'm not getting any voltage there when I push the button. The fuse is OK.

Cheers,
Chris

Edited by ChrisPap on Thursday 27th September 21:10

Edited by ChrisPap on Friday 28th September 11:24

[ChrisPap]

2nd post to add:

I've also checked the steering wheel button (which the handbook says is horn) and that works.

I'd expect the button to work a relay, but I can't find mention of a horn relay for the tamora anywhere (nor can I hear one clicking).
There's only one brown relay at the bottom corner of the fuse panel which is marked fuel pumps, though some parts site are listing the brown relay as for the horn.

But I have found that fuse #1 is not showing 12 volts, but in fact 0.1V. So problems upstream or problem in fusebox possible?

I'm getting quite frustrated now because I'm desparate to get the car MOT'd by Saturday before I go away for work again!

Will attack tomorrow with a clear head.

Edited by ChrisPap on Thursday 27th September 23:12

[shep1001]

ChrisPap said:

Hi Guys,

I've pushing on with rebuilding my car but can't sort the horn.

On a T350, I'm thinking that the horns mount to the same AV bobbins as the radiator? One each side?

And should the wiring for them be one black and one purple wire?

I can't see any other logical wiring for them but I'm not getting any voltage there when I push the button. The fuse is OK.

Cheers,
Chris

Edited by ChrisPap on Thursday 27th September 21:10

Is the earth OK? mine was a little iffy so I replaced the horn push (they can fail) & created a better earth. Is the horn not just a 'push to make' switch so there is no need for a relay?

Edited by shep1001 on Friday 28th September 00:34

[S6 Devil]

There is a relay for the horn on a Tuscan. I would have thought it's the same for a Tamora.

[ChrisPap]

Still not fixed but I have discovered that the T cars (at least) have a Relay and Splice unit (RAS) which sits under the central tunnel cover next to the ash tray. It's a ally box full of relays and inside looks like this:



Still haven't figured out what's going on with mine though. Would kill for a wiring diagram right now!

[ChrisPap]

Can anyone confirm that the horn should work with the ignition off?

[jrb43]

ChrisPap said:

Can anyone confirm that the horn should work with the ignition off?

Not by my car at present but imagine it must; sure I've knocked it by mistake. Furthermore, I can imagine an archaic rule that says you must be able to alert other road users when you've stalled, yada yada.

Think I remember you were desperate to get it MOT'd tomorrow? Is there a case for buying some aftermarket horn from Halfrauds and splicing it into some "always on" feed (part of the radio loom?) then reviewing things later? I'm the bloke who took all day to change his badges though so none of my advice ever comes with a money back guarantee....

[ChrisPap]

Guys, I've been through it all and it seems that the horn relay inside the RAS unit has failed. The horn switch signal is going in, and there is continuity between the outputs and the horn wires at the front. But there is no relay click.

I'm not sure what the other relays in there are doing, but some are clicking on with the sidelights and headlights. Not sure how normal it is for one of the 14 relays to fail, and so the whole box is junk (as they're soldered to the board)? seems a bit crazy. Anyone else had this?

Anyway, I'm going to get another RAS and fingers crossed, that'll work. If not, I'll have to cut into the chassis loom and fit an independent horn relay. What a palava!