Engine light on Horn not working any ideas?
 

Hi all, a week ago purchased a 99 Boxster . Coming home the check engine light went on. I live in RI and the next day it was like the antarctic and the battery died so I replaced the battery. I think I left the interior light on. So by changing the battery I reset the check engine light. So I have been driving it and check engine light went on again and the horn doesn't work. I checked the fuses for horn and there was a 30amp fuse where a 25amp should be so I replaced it. Horn still doesn't work when I press the steering wheel. I know in order to take apart the steering wheel with airbag I will have to disconnect the negative battery cable but I am concerned about resetting the check engine light again. I am currently driving on temp plates so I have to register the car and get it inspected. I am afraid that if I take it to be inspected and they detect the engine light has been reset too many times they will fail it then I will have more of a problem.

How should I proceed?

Either get a decoder (available on ebay for as little as $30 or ideally a few hundred for a durametric) or have your car decoded (most expensively at your dealer or for free at a lot of car parts shops like autozone). You need to know why the check engine light is coming on and fix it. You will not get failed for too many resets but you will for having a check engine light (or a pending failure which will also most likely show when you go to have your inspection).

The horn issue is probably not related to the check engine light. CEL is primarily reporting issues around emissions. Before you pull the wheel apart check if you have power at the horn itself when the button is pressed.

before pulling the wheel apart check not only the horn fuses, but there is also a horn relay in the panel above the fuse panel that may be the problem. You can get down in the wheel well and listen for a click from the relay when you press the horn button with the ignition on. If it clicks then everything should be good up to that point and it is probably your horns. They do go bad. I just replaced mine on my 04. Got a set of used ones on line for $20.
The check engine light may well be the maf sensor needs a good cleaning. Definitely the easiest thing to eliminate first.
I have manuals, etc and will be glad to talk you through both of these if you want to call me at 828 385 3100. good luck mountainman

Good luck with the new to you car.

If you plan to do a lot of work on the car yourself, then you'll find three things really valuable:

1. Durametic diagnostic tool - (versions 6 or 5)
2. Bentley service manual
3. 101 Projects book

You can find all of these things new or used on the web. The Durametric allows you to read diagnostic codes, test systems, and reset things like the CEL and airbag warning lights.

Horn not working
 

Ok turned the car on and pressed the steering wheel did not hear clicking from the relay so ordered a new one. as soon as I get it will let you know if it works.

If you end up needing horns, as I did on my '98, go to pelican. The horns are $12 each, are an exact fit, and have the proper connector. Great buy.

ok friends, got the horn relay and replaced it. I now hear clicking but no horn. short in the steering wheel? What do you all think?

If the relay clicks but the horns don't sound it sounds like the horns are dead or disconnected. Try pressing the horn buttons & see if you are getting power to the connectors on the horns.

Surprised tha you would have a bad relay AND bad horns but that's what it looks like. If your relay is clicking there is probably nothing wrong with the horn switch. Aside from horns not working it's also possible that the power supply from battery to relay is down. As suggested below, check if you have power at the horns when you push the button. If yes then the horns are at fault. If no, then the supply to the relay is probably your issue. Let us know.

In order to access the horns to check them, you are going to have to remove the bumper cover. Good time to do a really good cleaning of the radiators.

bought new horns from pelican. will keep you posted. bought a durametric and getting the message "cable not ready".

On the Durametric, make sure you install the USB drivers first. Then turn the key on & connect the cable. Wait for the steady green light. Plug the USB into your PC & wait for a couple of minutes & start Durametric. It can be finicky so you need to be patient. I spoke with them a month or so back & they told me the software runs on the edge of USB speed so longer cables & such can give you errors like that.

well I bought new horns from Pelican. took the bumper off and found the horns. I was only able to get off the bottom or High horn replaced it and it did the trick. went to Lowes and got a piece of flat stock iron from their hardware dept with some holes already predrilled and bolted it to a support behind the bumper and screwed the new horns onto that bracket so next time will be easier to get at. Sitting in my house and the horn is going off on its own. ran out there and lifted the top of the airbag cover and it shut off so I also have sagging rubber gromets. took the fuse out for now will put a piece of cardboard in when I have a minute. at least I am coming to a resolution. thanks everyone for your help.