Horn has failed

[sixvolvos]

Group:
2001 S60 2.4T
Only 70K miles on the car.
My horn has failed. Don't know how long it has been bad since I seldom use it.
Needed it badly a couple of days ago but no horn!
Fuse #9, 15 amp is good but that is all I can troubleshoot.
It is in the under-hood fuse box and does have power to it.
To be sure I had the engine running at the time.
The relay FM12 is good as determined by swapping it with another one.
There may be a related relay in the bottom side of the underhood fuse box, but I cannot get the top assembly off!
I see no reference to any horn fuses in the interior fuse box.
I checked the 5A fuse called steering column module, and it was ok.

The alarm horn went off last week, but I think that is a different horn. It was before I found the main horn not working.
My alarm module was changed out in March of last year, but now the alarm system does not flash the lights when locking or unlocking with the remote. The symptom then was the sunroof did not work.
The sunroof works now.

I'm afraid the alarm module is bad again, but that is an expensive $300 troubleshooting procedure.
Do all the S60 and S80 cars use the same module?
Has Volvo cured the battery leakage problem?

I can see the horn behind the grille, but I see no way to get at it without taking the entire front bumper and grill assembly off.
I have the lower panel off, but still cannot even see the horn from the bottom to see if it is getting power.

Any suggestions?
TIA

[otis44]

Can't help you on troubleshooting the horn, I have never heard of one failing. If you can get the grill out you will have easy access to the horn. The grill is held in by several plastic catches for lack of a better term. The ones on the top are easy enough to get to for the ones on the bottom you should be able to to remove the plastic push pins in the top center of the bumper cover and pull it back enough to get to the bottom latches. If you are interested I have an alarm module from an 05 or 06 car that I tested when I changed my wife's module about 4 months ago, I'd take about half of what new is and if i have a horn, which I think I do I'd throw that in as well.

[sixvolvos]

Otis:
I would be interested in the used alarm module.
Dealer says that '01 is the same module as '05 and '06, and same as S80 models as well.
Then the question is whether it is already corroded inside.
I'm sure you have heard that the internal battery leaks, and the corrosion destroys the circuit board.
My original module was badly corroded inside.
With care the module can be opened using X-Acto saws and knives.
I would want to know that yours is not corroded inside.
I can do the opening and I have the special electronic "silastic" to reseal it.
Why did you change the module?

As for the grille, I see none of the attachment devices you mention.
Probably the '01 was different.
I don't know how to attach pictures so I will send my address.
[email protected]

First I need to do a bit more troubleshooting on the circuit.

Thanks,
sixvolvos

[billofdurham]

The attached shows how to remove the grille.

S60 horn removal.pdf

(68.96 KiB) Downloaded 1057 times

Bill.

[sixvolvos]

Bill:
Thanks for the grille removal procedure.
I was able to get to the horn and test it as being OK.
Relay is good, fuse is OK, 12V available at the fuse and relay, but no joy.
Alarm works, siren sounds, lights flash, can be turned on and off with the remote.
Sunroof works which was a previous indication of failed alarm module.

Does anyone have the wiring diagram for the horn circuit?
Is there such a thing as a steering column module?
Where is it located?
There is a fuse for it which is OK and it has 12V to it.
That fuse is #23 and says: "Light switch/climate control module, OBD
steering wheel module" (sic).
Without a comma after OBD there is confusion about the systems affected.
All steering column controls work OK and the climate control system is OK.

Still looking for info.
Can anyone supply diagnostic info?
Thanks,
sixvolvos, who depends on these lists to keep the dealer from bankrupting me.