1988 Hi Ace horn not working

[Hbrent]

Hiya team,

 

I have a 1988 Toyota Hi Ace light truck.  My horn isn’t going, there is power getting to it so I bought a new horn, but still not working.  Any ideas?  I haven’t removed the steering wheel, could it be something behind there, even though there is power getting to it?  Any ideas appreciated.

regards

[flash22]

Does it have an airbag, the horn is ground side switched, have you checked the relay ?

[Hbrent]

6 hours ago, flash22 said:

Does it have an airbag, the horn is ground side switched, have you checked the relay ?

Na, no airbag.  Also no relay on 1988 Toyota Hi-Ace, I’m lead to believe?

[flash22]

Internal fuse box under the centre of the dash there are various fuse box types take a pic if you can

https://fuseandrelay.com/toyota/hiace.html

[Tintaglia]

Add a temporary earth to the other side of the horn, if the horn then sounds you need to find the open circuit.  The earth wire goes from the horn to the horn push.  Usually the horn push end is the culprit.  Have a look inside, probably a bad contact there.  On non-airbag cars there is usually a spring loaded copper tang in contact with a brass ring.  This tang can get bent away from the ring. You will probably have to take the steering wheel off to sort it.    

[flash22]

It's a switch negative on the control side of the relay, 1 fuse feeds both control and load sides of the relay, the simplest thing, being a truck is the relay has come loose

Just a general, non-specific to a model example

KGB10 horn diagram.pdf