buzzing after msd install

[chobracobra]

I just installed an msd 6al system and blaster tfi coil. When the sound system is on i get horrible rif interference and it buzzes like mad. But even when the system is off, i still hear what sounds like an insect trapped under my dash. Does it effect all electronics. Would an RIF filter help? thanks

 

[Daggar]

Going through and checking all of your grounds should be the first step. make sure they're GOOD grounds. If they look dicey at all then add MORE grounds. Also check the ground for the items that your new ignition is bonded with.

Example:
If the coil is grounded to the body then check the body grounds. If grounded to the motor then check the motor grounds.

I sounds as if somehwere, something is picking up some stray voltage and sending it through your wiring or chasis.

 

[srothfuss]

Just as Daggar eluded to. When you upgraded your electrical system for the ignition, you forgot to increase the amount of grounding for that same system.

W/O good grounds, your speakers will pickup EMI and thus, your buzzing.

Adding a ground from the coil bracket to the strut tower solved it for me, but I don't have a box on my car... Just a Crane coil.

 

[chobracobra]

Ok when the radio is on i get buzzing from the speakers. thats understandable. The constant buzzing is coming from the MSD box!!!!! what gives???

 

[Daggar]

That can be the result of that stray voltage that I mentioned before. If electricity is able to find a ground source because it's primary source is insufficient then it will, regarless of whether it's a good one or not. Rectifier circuits are not particularly fond of having to 'fight' for good current pathway. Start with making your grounds as good as they can be before we try and suggest anything further. Gotta rule out the possibilities.

 

[chobracobra]

How do you determine a good ground? The battery is in the trunk, so the battery ground is to the chassis in the back. the car ran fine (although before the msd my stereo made a quiet almost sounded like a roots blower sound that varied with rpm.) Could this be a start? the battery ground is bad? my dad is an electrician so i kind of have an idea of making good connections. (sanding paint). The msd, kill switch, engine, and some other ground are connected at 2 points on a very sanded down portion of the fender. what do you all think? daggar thanks so far for the replies

 

[Daggar]

I think you know what to look for and how to make it right. It will probably be pretty obvious to you what's causing all the trouble once you come across it. Good luck man... let us know how it turns out.

 

[chobracobra]

yea i will. when i get some daylight tommorow, i will disconnect the msd ground from the chassis and as a tempory test, directly ground it to the battery outisde the car with a long wire. 10 guage should do it. if it still buzzes im callin msd!! thanks daggar

 

[Shakerhood]

Are you sure its the MSD Box making the noise. MSD Coils are Notorius for making an audible humming/buzzing sound.