englundjd

I am having a problem with my amp randomly kicking off. I have tested and concluded that it is not the amp causing the issue so im wondering if the wiring is not big enough? its an 1850 watt max amp fed and grounded by 4 guage wire, the wire that runs from the amp to the subs is smaller.

The amp doesnt go into protect mode and it does not get hot. when it is working right it is getting 12.5-13.5 volts but when it isnt working it only gets 1-3 volts. I have found NO breaks or issues of that kind with the wiring. ive been trying to figure this out for quite a while

when it isnt working and it suddenly kicks back on it always manages to scare the **** outa me

Capricio

You're measuring at at the amp's main power terminal? Time to bust out a multi-meter with some long leads and when the voltage drops, start measuring at at different points, like the main fuse block (on the 4 ga), battery terminal, etc. Completely guessing but maybe a loose ground terminal or some kind of thermal protection in the line...

Freeman83

If you're using an agu(tube style glass) fuse under the hood, this is likely your problem. The cheaper ones will fail without blowing. Usually the solder inside melting and losing connection.

englundjd

we have checked it with a multi meter, when the voltage drops it drops in the whole wire, in front of the fuse to. What im wondering is if my ground is not good enough but i have it bolted into the body metal under the panel where the spare tire goes so i'd think its fairly solid.

I have had the power wire hooked up to the distribution block, the battery, and directly to the alternator (probably not smart but i wanted to try it).

I do not have a cylindrical fuse. its like this one


im going to go play with the ground over my lunch break and see if that makes a difference

TyCZ28

Check your ohm loads... if the subs are wanting 2ohms and your amp is only stable down to 4 some amps will cutoff the power source rather than go protect... its usally a result from the amp trying to draw more power from th battery... start there first..

Capricio

I'm not sure the car could even run if the voltage is 3VDC at the battery terminal. Even with a dead battery, you can run off the alternator and maintain 12+ VDC at the terminal while the engine is running. It seems like something on the hot side is grounding out, or you don't have a good ground where you need it.

Are you taking all these measurements while the car is running? If not, it could be some loose plates inside in your battery. This could account for the intermittent nature of what you are seeing, as the battery bounces around. Are you not noticing any other problems/symptoms besides the audio system? When you're at 3V, can you turn the car off and will it turn the starter again?

Maybe try rapping on the battery with a rod or something when the problem occurs. I had a battery once that would either perform perfectly, or I'd find it dead in the parking lot. I'd get a jump, drive it home, and it'd be fine the next 3 times I started. Turns out jarring it while it was playing dead would bring it around, as the dislodged plate would get back into position. My new battery I had a strap put over it to stop it from vibrating.

Do you have another vehicle you can swap side-post batteries between?

WhiteBird00

iTrader: (4)

Your amp ground would have nothing to do with it based on your testing. Assuming you're using the voltmeter correctly (red lead on the power wire, black lead on the battery negative terminal or a known good chassis ground point) then you have only 3 volts on the power side with the amp not even in the circuit. You need to look for a serious problem on the supply side rather than the ground side.

bajaboy501

Hey op I know you are going to say that you checked the fuse, but if the terminals are even just a little bit loose it will cause this issue. I just ran into it on a friend of mines car. The terminal that attached to the fuse was touching the fuse so I had 12 volts, but under any kind of load it would drop severely. I squished the terminal back together so it was tight again on the fuse and worked perfectly no voltage drop after that. Just an idea of what to check. Let me know if this helps.

englundjd

i think i solved the issue. It was a bad connection in the wire between the battery and the fuse lol. I got mad at it and shook the fuse holder and the subs kicked on so i played with it more and found the issue... i think. I'll take it for a drive tonight and see if it works like it should

Capricio

...kind of doesn't explain how it passed your earlier testing then, but whatever. Sounds like you have more than one intermittent contact to sort out. Or possibly you just have some corrosion on the battery terminal and need a wirebrush with some baking soda.