my engine light came on yesterday. after that it was idling fast and sputtering if I went over 30. I stopped, shut it off and did my errands. I came back out and my horn was going off. I found the fuse in the auxillary electrical and pulled it. Horn went off, and it is running ok, but engine light still on. Help!
For the engine light the first thing to do is have the trouble codes pulled & post them here.
In most states Autozone will pull the codes no charge.
In California, Autozone no longer pulls codes, but they will loan a code scanner & you pull the codes yourself.
One never knows for sure on these newer electronic wonders, but the horn should be totally unrelated to the engine light.
As with any electrical problem the first thing to do is to look at a wiring diagram & undertand how the circuit works.
Step 2 is to fix the problem.
Take a look at the horn circuit wiring diagram at autozone.com.
Likely culprits are a bad horn switch or grounded horn trigger wire.