Horn problems

[Bikercmbc]

when I bought my car neither of the horns worked. I purchased new horns from dmch and installed them. problems comes only when both horns are plugged in. if I plug each horn in individually and the other is unplugged then both work correctly. as soon as both are plugged in neither work at all all I hear is a little click with push of the button. anyone know what causing this, bad grounds, not enough volts when both are in???

[Jonathan]

Do your turn signal lights work as they should if you push up or down on the left steering column stalk?

Do your turn signal lights come on as they should if you press the hazard switch?

Can you get under the car enough to see clearly the wiring for the horns? It should look like this:

18977

The 12 volt wire to the horns labelled PB is purple/black. It is daisy chained together from one horn to the next and I'm wondering if this is related somehow to the problems you've described on your car?

Is your ground wire okay? Perhaps take it off and clean the contact point.

[Bikercmbc]

Yeah all the lights and turn signals work correctly. I've cleaned the main ground behind the drivers front wheel. There is some dirt on the bracket holding the horns to the frame. Just doesn't make sense why they grounds are good enough for the single horn to work but not enough to work together.

[Dangermouse]

Because by connecting the horns in parallel, you halve the circuit resistance and therefore double the current that needs to flow through that bad ground.

[Bikercmbc]

Yeah that makes sense. Ill clean the bracket and frame where they attatch put new bolts in and see what happens. Thanks

[dmc6960]

You could also jump a good 12V wire to them directly (I know they work individually, but force that 12v on them with the harness still attached so they'll both activate). That would tell you if the 12V line is perhaps the weak link. Most likely weak link point for the 12V is at the harness connectors in the washer reservoir area. With a helper perhaps you could also get a multimeter on those connections while its not working. Then if they show a really low or no voltage at the horn you can alternate a good ground or good 12v to determine which one is bad. I had to do this once to troubleshoot a fuel pump who's ground failed in the washer reservoir connector.

[David T]

You might also have a problem with the horn switch. The power for the horns goes through the horn switch, the Delorean has NO horn relay!
David Teitelbaum

[john 05141]

I read somewhere that it is a good idea to mount the horns facing backwards. If facing forward, it catches a lot of water and can cause malfunctions.
No idea of that is true or not, I do not have the original horns anymore anyway.

Jan

[jonas21]

The horns do not catch too much dirt or moisture when facing forwards, also they have good inner seals. I totally disassembled mine today and they looked brand new inside (no rust or anything).
Its better to mount them forward like the factory ment them to be.