Hey Guys, i've just finished doing an install in my friends 89 Crown Vic

Did everything A-Z, replaced H/U, front & rear speakers, and i got a 5-channel to power everything. Monster cable all around except for power and ground wire, its generic stuff.

now here is my problem, it'll play at low volume, but as soon as you turn it up, it cuts out, the amp goes into protect, and every second you get a pulsing noise. During these pulses, the lights dim. None of the fuses blew.

It's really weird, i have no idea what it is, its never happened to me before. I know everything is wired correctly. There are only two things that come to mind, the battery had just died earlier that day and didnt have much time to charge, and also im thinking alternators on 89 Crown Vic can't produce much amperage at idle. Is it possible there isn't enough juice for the system so the amp is going into protect, and those pulses every second is the amp trying to come back from it?

Let me know guys, any feed back would be appreciated. Thanks.

 

i would start with your grounds make sure that your ground to chaisis from your amp is clean and secure did you sand down your connection so that there is no paint , is your alt. to battery wire big enough and is your battery to ground wire a decent size aswell , if thats no good then id set up a dmm and watch your voltage as your system pounds as loud as you can get it before the terrible old cut out

 

Thats a good start there. If you list all gear used we can maybe see if there are any other issues that might cause this. Wire, and fuse sizes, what amps, head unit, speakers, etc.

 

May need an alternator upgrade...

 

thanks guys, i'll give it a shot. I actually didn't sand down the paint. It was the only spot in the crown vics trunk where there was a bolt, and it was already housing a ground wire, so i figured id be safe. i'll definitely try doing the big3 and sanding my contact points and let you all know how it goes.

 

thats the first thing that came to mind. Crown Vics in 89 had no electronics. Power windows, power locks and a radio. Has an EFI fuel system, but nothing special, so i wouldnt be surprised if its below 50amps. Even less at idle.

 

My 1990 crx and civic have no power options except sunroof..
Its a stock 60 amp alt..
I have a program that tells you exactly how many amps you need from your alternator, depending on how many watts you have.

Question for the original poster...
how many RMS watts does your system put out roughly ?
I can tell you how many amps you need from your alternator at idle.

 

The pulsing noise, causing the lights to dim etc..., I experienced that exactly, but it happened mid-drive, and even with the deck off, it kept going.

I determined the deck died, something fried in it, and now have a new deck (rest of setup the same) and no problems.

Tim

 

its roughly 1500 WRMS, so id need a 125 amp alternator, i checked and the stock one is 60amp. But still, at the volume it cuts, im not even pushing 400 watts.

i've still got to try some troubleshooting, ill re-do grounds and if that doesn't do it ill swap the H/U. If it continues i'll record a video of the problem to give you guys a better understanding of whats happening. Thanks for the input!

 

Well easy way to determine if it's your car's electrical system is to turn all accessories on...wipers, defrost, blower, etc... If the car's electrical system has no problems with all those running, then with them off, it should have no problem running your audio system at low to mid output. More than likely it's a bad ground, a bad component...deck or amp, or install issue.