CEL When Headlights Turn On...

[DSM_PWR]

So i was driving the other night and i flashed high beams and all of u sudden my radio turned off and a CEL came on. Within 5 sec the CEL went away so i cant hook up the logger and check out the code. NOW the CEL turns on "sometimes" when i just start the car and turn on the headlights. Anyone know what i can be? im thinking alternator or alternator fuse...

Also at one point when i flashed my high beams my horn honked until i disconnected the negative terminal. when i re-connected it stopped...

 

[bpestilence]

Sounds like you have serious wiring issues. The high beam relay is somewhow causing the horn relay to close, and is cross-firing over to the ECU wiring. I would recommend you look in the fuse, relay box under the hood. Make sure the relays are working properly and that the wires are in good condition. This may be a problem that is very difficult to trace.

 

[luv2rallye]

Check alt fuse and measure battery voltage with engine running and high beams on to make sure alt is working - should be over 13V.

 

[DSM_PWR]

yup my dsm ate the alternator fuse i smelt buring for a while before i realized it was the fuse buring. is there any reason it would eat it? i dont recall ever toucing the alternator with any socket or metal, but then again it has been raining, would water from below make it burn fuses???

 

[luv2rallye]

Water being a conductor can short out anything.