high buzzing noise from back tweeter

Just a couple weeks ago i got 4 tweeters installed. 2 in the front corners of the windows and the back ones right by your ears when ur sitting in the back seats right next to the seat belt. Everytime i turn of my head lights the back left tweeter buzzes. Can anyone give me an explanation for this?03 F150 on 24's

HU:Pioneer DVD5700

Frt:MC57

Subs:(12)S12L7

Amps:(3)KX2500.1's, MC-2004

Could be a bad ground on whatever amp is driving the tweeter, a bad crossover ground, or a speaker wire touching ground.Support the12volt.com

my head unit is powering the door speakers which the tweeters are wired with the door speakers.03 F150 on 24's

HU:Pioneer DVD5700

Frt:MC57

Subs:(12)S12L7

Amps:(3)KX2500.1's, MC-2004

The tweeters are in parallel with the door speakers?  I hope you are using a proper crossover on the door speaker as well as the tweeter to avoid overloading the HU amps... but back to your problem, assuming the door speaker is not also "buzzing," I suspect a bad crossover or a frayed speaker wire touching ground.  Or the tweet could be blown (but then it would more likely buzz all the time and have nothing to do with your headlights.)Support the12volt.com

they are wired parallel but no crossover. Is that bad? am i supposed to have a crossover?03 F150 on 24's

HU:Pioneer DVD5700

Frt:MC57

Subs:(12)S12L7

Amps:(3)KX2500.1's, MC-2004

Yes!  First off a tweeter needs as a minimum a high-pass crossover to protect it.  If whoever installed your tweets did not install a crossover, that person has set you up to blow those tweets pretty quickly (which may be what you are hearing.)  Secondly, if the door speaker and the tweeter are in parallel, even with a crossover on the tweeter this places a 2-ohm load on your HU in the tweeter operating band (guessing assuming both the door speaker and the tweet are 4-ohm speakers.)  Most if not all heads are not designed to sustain a 2-ohm load and you will overload it and cause distortion (which is also what you might be hearing) or you can blow the HU amp.  You need a dedicated 2-way crossover to run speakers in parallel like that and to ensure you are not setting yourself up for damage.Support the12volt.com

ok thankyou very much for the info. Im going to just take the 2 back tweeters out and use an amp to power the new 2 front components and the back 3 ways. Is that ok?03 F150 on 24's

HU:Pioneer DVD5700

Frt:MC57

Subs:(12)S12L7

Amps:(3)KX2500.1's, MC-2004

A good component set in the front powered by a good amp, and whatever door speakers you want in the back powered by the HU is a fine way to go.  Get rid of the extra tweeters unless you really need them and they are set up correctly (which they are NOT right now!)Support the12volt.com