Why would the horn stop working after driving for a few miles.

I can get in the car, start it, try the horn and it works fine. However, by the time I drive to work (15mi) the horn has stoped working. All I can hear is a week sound, like when the battery is dead.

I've replaced the fuses, the car starts fine.

Fortunately the inspection place was nearby so the horn worked when I got there.

Any ideas??????????

__________________
84 300D 251K
87 190DT 281K - Sold
06 Ford Escape 172K
94 Ford Ranger 250K
99 Chevy Suburban 181K

I too have similar problem. But mine I know is related to AC fan etc.
Well when I have AC on, Aux fan on, Blower motor at full, after about 20-25 minutes run, I get the weak honk. Then I turned offf the blower, the AC etc, and 2-3 minutes later its all ok.
I suspect either a weak battery- though I have no problem in starting but will get it load tested .
or a weak alternator.
I hope its the first one. See if you have similar problem while AC and other amp suckers ar on. Then try turning them off and see if you get your normal honk back in few minutes.

MVK

__________________
One penny saved is three penny earned.

1985 300D Turbo 179,000miles

I was also thinking battery or alternator. Problem is I don't see any other symptoms. I'll have it checked this weekend.
Thanks for the reply.

__________________
84 300D 251K
87 190DT 281K - Sold
06 Ford Escape 172K
94 Ford Ranger 250K
99 Chevy Suburban 181K

My car too does this... I think its a loose wire, having to do with the vibration of the motor....

It might also be worth pulling the steering wheel and looking at the way the horn contacts and springs are. I had kind of the opposite problem, where the horn would be constantly on and found out that one of the springs was missing and contact was being made almost automatically. I could see where a spring or springs was too brittle to allow good contact between the two plates which operate the horn in the first place.

You might actually be able to do the check by just pulling the cover off the horn button.

__________________
1987 300SDL 265,000 mi.
1982 300SD 325,000 mi. (and holding)
1956 Packard Clipper 150,000 mi.

I know this has been awhile, but I finally got around to fixing the problem (time for the annual inspection). Basically it was the horns themselves. With the new horns, all the quirky electrical issues have gone away.

__________________
84 300D 251K
87 190DT 281K - Sold
06 Ford Escape 172K
94 Ford Ranger 250K
99 Chevy Suburban 181K

thanks for the follow up.
MVK

__________________
One penny saved is three penny earned.

1985 300D Turbo 179,000miles