There is no need to ground your audio system on the battery. I'm not sure why so many people think that is necessary. For amps especially, the shorter the ground the better (I know you said your amps are grounded to the hatch latch). You should ground the amps right to the chassis less than 8 inches long if possible. If you do this, I bet your amps will run cooler with more power. As for the other stuff, try grounding that to the chassis also and not on the battery. It may even help your voltage drop since most of your car's electrical stuff is sharing the battery ground the way you have it hooked up.

thanx FC, gonna go out and do that in just a sec...any good grounding points in the engine bay BTW?? that's y i ended up using the - post...didn't want to take off any bolts to ground...

Actually you want to ground the amps to the battery.. RX-7's FC and FD are renound for having shity ground problems due to the bad ass non rusting metal mazda used in the cars.. also grounding the amps to the battery will give you a better sound quality... copper conducts electricity way better than steel... The larger wire you use the less resistance, so you sould run a 4 guage from the - batt teminal to near the amps then use a ground block and run the short 8 guage wires in to that block.



What you need to do is run anouther ground wire directly from the - batt terminal to the altenator mounting bracket so the altenator has a good ground directly to the battery.. You may also want to run a 4 guage wire from the alt + votage out post to the + on the battery.. you should also clean the posts on your battery and terminals then go around the car and pull off all the grounds and clean them up with a wire brush.. It just sounds like your having ground issues and the altenator is still probably good..



The ground points will oxidize over time so you should do this once a year or so to keep the charging system working at it peak ability.

I understand what you are saying about copper conducting electricity better but it's always been my understanding that the battery, alternator, engine, and everything electrical ends up grounding to the car since the chassis is obviously the largest solid metal ground. I don't understand how there is an advantage of running all these things through the battery post. Don't they end up grounding back to the car anyway? Maybe I'm way off here, I just was always told the shorter and thicker the grounds the better. When diagnosing amp problems, I usually found a sound improvement from changing to a thick and short chassis ground.

LOL....take out the system and you'll be faster https://www.nopistons.com/forums/pub...#>/biggrin.png







just my 2 cents

I see a few problems here...

You should be runnng a ground wire (from the amps) that is the same size as the largest power wire going to the amp. In this case you are kind of screwed because that would be a 2 ga wire, and that won't hook up to your amp. So if you are running 2 ga back to a distribution block, then to 8 ga to the amps, run the same as a ground; 8 ga into a distribution block to 2 ga.

It does not sound like you have a good grounding point. I like to find a good place close to the amps (make sure it's not right above the gas tank, ect.), grind away any paint (get down to bare metal), drill a hole, tap it, then hit the bolt on wire wheel so it is nice and shiny and use that to hold the ground wire to the metal. Also it is recomended to have your grouund within 18" of the amp, the shorter the better. Like Dragon said, RX-7's FC and FD are renound for having shity ground problems.. so it wouldn't hurt running a ground wire from where the ground wire is bolted to the chasis up to the - terminal of the battery. Also run a couple of big grounds from the - battery terminal to the engine then to the chasis and one from the terminal to the chasis.

Also, I think I read that you have a fuse/distribution block in your ground wire, that is useless, get rid of it. If anything it is hampering your grounding because the current has somewhat of a bottle-neck at the fuse.

Getting a cap would help you out too.

I used to work for a car audio store, and did installs on the side for over 5 years. I've had a car take 9th in it's class in a stereo competition (maybe I'll scan some pics of it and post them), also I had a truck that could hit 148 db, and then it broke the RTA.

Yeah, what cabrio said, only thing I would add is to use a star washer and/or nut and bolt.

I figured that was a given, but maybe I should have added that it.





Me too! :stickpoke: