I raced the car yesterday and the trans-brake let go twice before I was ready to leave.This morning I went out to check thing's out and the car was dead but the problem is Im not sure if I turned the kill switch off.I got it charged back up and turned the key on and heard a buzzing noise coming from my msd box(7al2).I also noticed yesterday that my tach kept needing reset to the desired shift point.Today once I got it charged and heard the buzzing I pushed the trans-brake button and the tach needle would move.I unpluged the tach and replug it again and now everything works ok and the buzzing is gone.Is the box going bad or is something eles going on?THANKS,DRIVER,BILL

The MSD box should be potted solid state electronics - shouldn't be anything in there to buzz. Are you sure it was coming from the 7AL? Sounds like you have some wiring problems. Maybe a bad connection or two, a chaffed wire and a short, etc. I would check over your wiring before you swap any high dollar elec. parts. Verify where the noise is coming from for sure.

Thanks,I thought about a ground? I do use a retrad box and have a rely hooked up to my nitrous and trans-brake to stop the nitrous from coming on untill the trans-brake button is released.This is not a home made deal..I bought it from NX.Could this relay be going bad?

Really don't have the answer to your question (have no experience with 7al2)
Try searching or posting your question at http://www.msdignition.com/forum/
MSD factory techs post there, usually will get a reply in a day or so from one of them. If you find the problem, post back.

Thanks undee70ss,I made a post there yesterday and still waiting.Maybe today.How have you been?Haven't talked with you since last winter.Hope things are going well.BILL

I'm not sure if the buzz is the box or not.. However is the box mounted anywhere where in could possibly get wet?? I know a few people that have had their MSD box go out due to water getting on or in it. I mounted mine on the inside the firewall behind the glove compartment to keep from this happening.

Thanks,mine is mounted inside the car but now other things are showing up and Im trying to figure this thing out.Since making this post I charged the six month old battery up and the very next day it was dead DEAD.Yesterday I recharged it up again and unhookthe nitrous and trans brake relay to see what what happen?Got home today and the battery was dead.The reason I unhook the nitrous and transbrake is those are two of the three thing's that have power all the time and the other being the fan relay other than these three thing's nothing eles has power untill the kill switch is turned on.What in the world is pulling the juice out of my battery??ANYBODY?
THANKS,BILL

It could just be wiring starting to get old or maybe the battery. Volt drop or drops somewhere.... I just had my whole car re-wired.. The old wiring was so bad to the point where i could not take my car out to any car shows or turn the motor off unless I was back home. If I tryed to start it back up I would get nothing. I had to put the battery on a charge before i took it for a drive... I run an Optima (red top) battery as well

I know what you are saying there because I did that six months ago and the battery and alt are less than six months old.I don't mind working on much of anything but I hate the electrical and wiring stuff.

Yup wiring is the one thing i can't and wont do... i took mine to a shop to have it all re wired. They did an awesome job, tough it was a hot rod shop so you pay for what you get