My horn as started having problems - which is bad because DC has a _lot_ of bad drivers. If i'm sitting at a stop light and the engine is just idling - the horn will not work. But if I blip the engine, the horn works while the RPM's are up. My first thought is that my battery might be going bad. I did wake up to a dead battery saturday morning. I spent friday bleeding the brakes (changed out the caramel colored brake fluid for something a bit more clear) but the brake lights don't come on when the ignition switch is "off", right?
Or maybe the horn is going bad and wants a higher voltage to work?


PS: I was at my local autozone - and wanted to pick up a new oil filter. It appears that STP has recalled the SM0-00 filter - i guess they realized that they were putting the wrong filter in a lot of those boxes.  Should I just go ahead and order a bunch of filters online?

I also just started having problems with my horn.  The horn does not work at idle or steady engine speed.  The horn only works when I rev up the engine.  This is a safety problem.  I too believe this is a battery issue.  I need to purchase a battery tender ..... any suggestions?

Have you checked any of the wire connections for corrosion?

I'll check the connections this evening.