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Is my BJ8 horn switch connected to ground positively or negatively?

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K

KSchoknecht

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Greetings all - - I have a 1966 BJ8 (HBJ8L 33606, built in November 1965) with an anemic horn that larger (that is, all) other cars don't hear. I just bought a pair of Hella Sharp Tone horns from Moss Motors. The diagram that accompanies the horns (attached) shows I should wire the horns as shown in Graphic 2a if the horn switch on the steering wheel is connected to the ground negatively, or as shown in 2b if the horn switch is connected to the ground positively. The icons that appear in the diagram aren't familiar to me.

How do I know whether my horn switch is grounded negatively or positively?

Also, the diagram appears to show a 16-amp in-line fuse between the battery and the relay switch. Don't I already have a fuse for the horn in the fuse box? Do I need to install another 16-amp fuse as shown in the diagram, or will the existing one suffice?

Many thanks in advance,

Kim
 

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  • Hella horn wiring diagram 1.jpg
    Hella horn wiring diagram 1.jpg
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Look at the battery connections, the general situation is that your car should be positively earthed that is + to chassis. If this is so, then all you should need to do is swap over the existing connections onto the new horns.

Your diagrams indicate the use of relays, normally your car would not have them.

In line fuses are OK if you do not want other associated circuits to go down if there is a fault with the horns, you can leave it out if you wish.

You can check you original horns by removing them from the car and checking them directly on the battery by using wires with crocodile clips, ( I find that these give a measure of control on your connections.) if you are positive earth connect the metal of the horn to the + terminal and run a wire from the -ive side of the battery to the terminal on the horn, briefly touching it, the horn should work, you can check out the new ones in the same way.



:cheers:

Bob
 
Thanks, Bob and Steve. You were right, Bob - - all I had to do was switch over the wires. The horns are a huge improvement. And I've ordered the wiring diagram, Steve - the perfect wall hanging for my garage - - -

Kim
 
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