• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

horns

Share this page

tahoe healey

tahoe healey

Yoda
Country flag
Offline
A while ago I purchased a pair of Healey original horns with the hope of adding them to the system to give a greater sound to awaken those who don't see me. I have restored them to very functional that I will hide somewhere inconspicuous. I am now not sure how to add them to the two that are the originals (BJ8). I don't want to blow fuses or diminish the volume of the original ones. Any thoughts? Can this be done?
TH
 
Hi TH:
If you still have the original fuse in the circuit it will not blow the fuse,more margin can be gained by insuring that the fuse is of the slow blow type.Paralleling the additional horns with the existing ones will allow you to complete the circuit
 
You may not blow the fuse because I believe the horn is feed from the larger of the two original fuses, but I might believe that you may create a voltage drop because of the small wire that is supplying the original horns at the original horn location. This will do two things. It will weaken the effectiveness of the horns and it will create a larger current draw because less voltage then requires more current to supply the equivalent power. Ex: (W = E X I ) which is Watts = Electromotive Force in volts X Intensity in amps. If you reduce the " E " it takes more Amps to get the same power. If you add horns it needs even more Amps. I would just supply the horns with a new larger wire.
 
vette said:
You may not blow the fuse because I believe the horn is feed from the larger of the two original fuses, but I might believe that you may create a voltage drop because of the small wire that is supplying the original horns at the original horn location. This will do two things. It will weaken the effectiveness of the horns and it will create a larger current draw because less voltage then requires more current to supply the equivalent power. Ex: (W = E X I ) which is Watts = Electromotive Force in volts X Intensity in amps. If you reduce the " E " it takes more Amps to get the same power. If you add horns it needs even more Amps. I would just supply the horns with a new larger wire.
Click to expand...

This happened to me with my heater blower. When running the blower, my voltmeter would drop from 13.5 to under 13. Installing a relay at the blower and using the stock wire to trigger the relay removed the voltage drop.
 
Well Steve

I agree in the case of a motor that runs continuously you will see a voltage drop as the wire resistance will increase due to heat.
Consequently, the voltage at the motor will drop some what.

Contrastingly, the horns are what we call low duty cycle devices since they only operate briefly when we push the horn button therefore they only expend a few joules of energy not large amounts of Watts.

OTOH, The relay will reduce the load on the horn contacts in the trafficator if there is a concern.
 
Power is Power, I don't care what unit you want to measure it in. The more power your load is going to use the better your voltage needs to be. A relay with the load side contacts supplied by a large wire from a good voltage source will solve the problem. Just don't start to overload the whole Healey electrical system. The wires are pretty small and the generator is only 15 to 30 amps. So where are you going to pull the larger wire from that supplies the 4 horns with good voltage and plenty of amps. Maybe your solenoid ????.....or maybe pull the larger wire all the way from the battery ... real pain there? If you hook it up to any other wire on a stock Healey wiring harness you are supplying the larger wire from a smaller wire. It might work to a point. Good Luck.
 
Back
Top