Horn + general electrical questions

[posplayr]

Honestly, it was barely dirty or corroded at all to begin with. I cleaned up the button contacts (just a bit of corrosion) with some steel wool and sprayed the gunk off with wd-40. I have been testing the DC voltage with my multimeter; what should I check with the ohm meter?

I understand that wd-40 might not be the best for electrical stuff, so if I need to take the thing back apart I will. I just didn't have any other cleaners on hand.

Do you have any Naval jelly? use that to clean the contacts and crimps. There is usually corrosion inside of the crimps. Of course after you do this the copper is bare and it will corrode again. That is why Detox-it is recommended it leaves a weather proofing. I usually just flow some solder into the crimps of critical connections.

To use the ohm meter, disconnect the battery ground and measure the resistance from the battery (+) post to the O and O/W outputs

[exzachtly1]

Do you have any Naval jelly? use that to clean the contacts and crimps. There is usually corrosion inside of the crimps. Of course after you do this the copper is bare and it will corrode again. That is why Detox-it is recommended it leaves a weather proofing. I usually just flow some solder into the crimps of critical connections.

To use the ohm meter, disconnect the battery ground and measure the resistance from the battery (+) post to the O and O/W outputs

I should clarify... I cleaned only one connection inside the switch, the connection that I understand to be the one that goes from the switch the ground (pictured a couple of posts back - the one I mentioned as having some gunk). Are you saying I should go through and clean all of the connections along the bike?

For the ground measurement, I'm not sure which O and O/W outputs you mean. Are these near the battery? Is the point of this to test the main ground from the battery?

[posplayr]

I should clarify... I cleaned only one connection inside the switch, the connection that I understand to be the one that goes from the switch the ground (pictured a couple of posts back - the one I mentioned as having some gunk). Are you saying I should go through and clean all of the connections along the bike?

I have not been following this thread in it's entirety but was just giving some general recommendations. I know Steve was helping but you still seem stuck.

I drew a simple diagram of the circuit with color codes. I was mistaken about the O/W; this is an O/G circuit coming from the fuse box. See the attached figure. I think Steve described this before but if it was not clear the horn is operated with what is called "low side" control. That means the horn will not operate until current flow through it. The high side (+) is always connected (albeit switched through the ignition switch), and the horn is operated by grounding the green or low side of the horn. This operates essentially just like the solenoid.

I would go about this basically as follows.

1. make sure that you have 12V at the horn O/G (if not go back and start at the fuse box O/G and go to the Horn O/G )
   
2. measure the voltage at the green side it should go from 12v (with horn off) to 0V (with horn on). (If not check the horn button for functionality using the ohm meter)
   
3. Disconnect battery (-) and verify the horn button is OL (when button normal), 0 ohms (when button depressed).

[exzachtly1]

I have not been following this thread in it's entirety but was just giving some general recommendations. I know Steve was helping but you still seem stuck.

I drew a simple diagram of the circuit with color codes. I was mistaken about the O/W; this is an O/G circuit coming from the fuse box. See the attached figure. I think Steve described this before but if it was not clear the horn is operated with what is called "low side" control. That means the horn will not operate until current flow through it. The high side (+) is always connected (albeit switched through the ignition switch), and the horn is operated by grounding the green or low side of the horn. This operates essentially just like the solenoid.

I would go about this basically as follows.

1. make sure that you have 12V at the horn O/G (if not go back and start at the fuse box O/G and go to the Horn O/G )
2. measure the voltage at the green side it should go from 12v (with horn off) to 0V (with horn on). (If not check the horn button for functionality using the ohm meter)
3. Disconnect battery (-) and verify the horn button is OL (when button normal), 0 ohms (when button depressed).

Thanks for the info, I just did the tests you indicated and here are the results.

BATTERY:
12.5v with key off
11v key on

CONNECTIONS AT HORN:
KEY ON:
~10v at G and G/O wires

KEY ON, BUTTON PRESSED:
3.2v @ G wire
7.2v @ G/O wire

BUTTON (with neg battery terminal disconnected):
Normal: 1.2 Ohm
Pressed: 0 Ohm

Obviously some bad results, but I'm not sure what exactly they mean or where I should look to next.
I want to make sure I did the last test correctly, too - here is a picture to illustrate where I tested:



Is that correct? It's a little hard to see the black terminal as it is under that other wire. But it looked right to me based on what I saw when I had the switch completely apart.

Any ideas??

[posplayr]

Thanks for the info, I just did the tests you indicated and here are the results.

BATTERY:
12.5v with key off
11v key on

CONNECTIONS AT HORN:
KEY ON:
~10v at G and G/O wires

KEY ON, BUTTON PRESSED:
3.2v @ G wire
7.2v @ G/O wire

BUTTON (with neg battery terminal disconnected):
Normal: 1.2 Ohm
Pressed: 0 Ohm

Obviously some bad results, but I'm not sure what exactly they mean or where I should look to next.
I want to make sure I did the last test correctly, too - here is a picture to illustrate where I tested:



Is that correct? It's a little hard to see the black terminal as it is under that other wire. But it looked right to me based on what I saw when I had the switch completely apart.

Any ideas??

first as you already know the battery is in poor shape, but it might be even worse that you think without the horn, it is already dropping to 10.0V which is about 1.2V lower than it should (12.2-12.4v with key on is a healthy battery)

now there two measurements are interesting because if your are on the high side (of the horn), then you should be at the battery voltage and if you are on the low side you should be at ground (i.e. 0V). Anything else and there is resistance in the current path other than the horn.

With the 7.2V on the G/O see how much the battery is at; is it also at 7.2V or maybe a little higher? If he battery is still at 10V you have a huge resistance somewhere between the battery through to the ignition switch and fuse box back to the horn.

The 3.2V on the G is saying that your horn button is dirty and needs cleaning.

[posplayr]

Is that correct? It's a little hard to see the black terminal as it is under that other wire. But it looked right to me based on what I saw when I had the switch completely apart.

Any ideas??

Assuming the black wire is the same at the connector and follows the B/W into the harness you are OK. You can also put the black lead into the back of the connector, but do not open it else you will break the path.

see attached for test points on horn switch

[exzachtly1]

first as you already know the battery is in poor shape, but it might be even worse that you think without the horn, it is already dropping to 10.0V which is about 1.2V lower than it should (12.2-12.4v with key on is a healthy battery)

now there two measurements are interesting because if your are on the high side (of the horn), then you should be at the battery voltage and if you are on the low side you should be at ground (i.e. 0V). Anything else and there is resistance in the current path other than the horn.

With the 7.2V on the G/O see how much the battery is at; is it also at 7.2V or maybe a little higher? If he battery is still at 10V you have a huge resistance somewhere between the battery through to the ignition switch and fuse box back to the horn.

The 3.2V on the G is saying that your horn button is dirty and needs cleaning.

Thanks for your help, this is my first time messing with this stuff as you can probably tell. Before yesterday even my basic electrical knowledge was shaky at best... been learning a lot the past couple of days.

I'm going to pull the battery and take it for testing first thing tomorrow; if it's indeed bad then I will replace. I guess I'll be cleaning the button again too with some appropriate cleaner, but I swear it was super clean - I'll take pictures next time I have it apart.

I'll check the battery for resistance like you said - but will have to wait til tomorrow.

[exzachtly1]

Whelp, you were right - turns out my battery was totally junked. It failed right away on the CCA test, was only putting out like 86 CCA.

I splurged and bought a nice sealed AGM battery. Hooked it up, and immediately the horn works just fine. Nice strong, loud honk! Also the bike starts much easier and seems to idle better.

I checked the horn wires again and now getting around 11v at the wires. I skipped testing with the button depressed because I didn't want to annoy the neighbors too much and, well, it's working just fine.

Thanks for all the help, as usual.

[posplayr]

Whelp, you were right - turns out my battery was totally junked. It failed right away on the CCA test, was only putting out like 86 CCA.

I splurged and bought a nice sealed AGM battery. Hooked it up, and immediately the horn works just fine. Nice strong, loud honk! Also the bike starts much easier and seems to idle better.

I checked the horn wires again and now getting around 11v at the wires. I skipped testing with the button depressed because I didn't want to annoy the neighbors too much and, well, it's working just fine.

Thanks for all the help, as usual.

I looked at how a horn works, it is an electromagnetic voice coil that has a series switch that is activated (opened) once
The coil gets to maximum. So the coil must be relatively low resistance on par with the switch resistance. Your battery was so low that you could not get the series switch to open and so we see the voltages you measured.

[exzachtly1]

I looked at how a horn works, it is an electromagnetic voice coil that has a series switch that is activated (opened) once
The coil gets to maximum. So the coil must be relatively low resistance on par with the switch resistance. Your battery was so low that you could not get the series switch to open and so we see the voltages you measured.

Awesome, makes perfect sense. I'm glad that's all it was!