I recently had to change my sub box in my car and removed my amp which was mounted on my box. So when I re-hooked up the subs to the amp, I blew the in-line fuse. I replaced it and then I blew the 2 fuses on the amp. I never disconnected any power/ground/RCA cables except for the wires coming from the back of the sub box. So why do the fuses keep blowing??? Please help because I am running out of ides BTW its a Kenwood KAC-7201 amp.
Unplug the speaker wires from the sub box.....Look very close at them. Make sure no strands of wire from one of the cable sides are touching any wire from the other cable side....If no wires are touching that is good....With them still unplugged, turn on your system and let it play....Do the fuses blow? If yes, disconnect the speaker wires at the amp end, try again....If they still blow, then you have to try disconnecting the rca's....if they still blow then possible ground or power problem shorting.....If they only blow when subs are hooked up, could be problem with the subs or the wiring between the terminals and the subs themselves.....It sounds to me like something is wrong like a shorted speaker or something grounded creating a dead short... Willy
I am thinking it is a short somewhere. I am wondering if its not my grounding point. I just searched a bit on other forums. I currently have the amp grounded on a bolt that holds a bar that runs over (but does not touch) the battery. I think that is my next move. Thanks Willy.
By the way, I read somewhere else that a neg battery terminal can be used as the grounding point as a last resort. I always thought that was a no-no. Any thoughts?
You want to make your ground path from the amp to the ground as short as possible.....The biggest ground wire on your vehicle is the chassis...If you upgrade your big three (or at least check clean and secure the current grounds), then your chassis is perfect....If you were to run a wire from the amp to the battery ground, it will be far less large than your chassis....if your chassis is grounded like it should be, a clean tight ground near the amp is the best bet. Your problem does not sound like a weak or bad ground....It sounds to me like you have a short causing high current flow and that is what is blowing your fuses....It is somehow in the circuit of the amp and the speaker (sub box)... What amp is it and how do you have your subs configured and running? Meaning what load are you presenting to your amp.....if the amp can handle only as low as 4 ohm and you configure it to run 1 ohm, the high current can blow the fuses Willy
I posted this a while back....there is other info on this too...under the automotive electrical section of this forum... Power And Grounds..... I figured I might just put a little thing together in this section to help out some in need of understanding some basic electricty things that are common to all automotive audio applications...... First off (pardon me those of you who know this like the backs of your hands...and I am not gonna delve into the electron therory of power flow that runs negative to positive, just basic stuff...) Let me give an example of the most basic circuit in 12v automotive....a light bulb.... In this circuit you need to have (as in every circuit) three basic things.. 1. battery 2. conductors (wires) 3. load (the light bulb) Current flows out of the battery from the positive post, through the wire, into the light bulb, through the filiment, then out of the light bulb through the wire back to the battery and you have a complete circuit....Since the light bulb is the only load in the circuit, it uses all voltage available....if there were two light bulbs (wired in series) each would use half of the load ( 6 volts each)...After the last load in the circuit, the wire leading back to the battery (ground) should have no measured voltage in it.... So if we were gonna use a volt meter and check some things, here is what we should find where....Across the battery we should have 12 volts....If we keep the black meter lead on bat. neg. and put the red lead just in front of the light bulb, we will read 12 volts....on the other side of the light bulb (if the bulb is good and lit) we would read what voltage there?....ZERO... If we read ANY voltage after the light bulb what does this tell you??? It tells you that from that point to the battery neg. there is another load. Now if you have a bad connection or corrosion in that wire, it is going to act as resistance (a load) in the circuit..... So let's plug in a car audio circuit and apply the principals.....Let's say it is the wiring of a single amplifier.....We measure battery voltage at the battery and have 12 volts....if we leave the black meter lead on bat. negative and move the red lead to the amp positive power terminal and our reading is 10 volts, what does that tell you? it tells you that between the battery and the amp, there is another load...if this wire is direct from the battery to the amp it should read the same voltage as the battery....A bad connection or corrosion is likely to cause this voltage drop...If you move the red lead to the negative terminal on the amp, it should read zero.....if it has any voltage in it, that will indicate a bad ground (connection, corrosion, etc..) Most times the amp is grounded to the chassis or body of the vehicle....The chassis and body are basically just huge ground wires so wherever there is a ground cable or strap from the battery to the chassis it just allows the chassis to be connected to battery negative...Sometimes the battery ground is a single cable that connects to the engine and then the engine may have points to connect to the chassis....All of these places are places to look for bad connections if you read voltage on the ground circuit..If your car has no direct connection from battery to chassis (ground), it is a good idea to install one just to make sure of a good chassis ground...Unless you put a wiring harness in yourself to run your audio grounds back to the battery direct, all of your audio components will ground to the chassis (bad grounds at these places can be the source of noise in the audio system) and depend on the chassis being properly grounded..... Hopefully this will give you a little knowledge about how to check for actual power and grounds in your audio circuits.... thanks Willy
hmmmm i know i'm late to the game,but it sounds like a shorted speaker. had a bud with the same prob.he took out his subs to re wire his new amp,and re wired them wrong. his amp didnt blow fuses.instead it just went into protect.
Here is what I am working with: Amp is Kenwood KAC-7201 800 W Max. Subs are (2) Pioneer TS-W305C 800 W Max. I also thought at first it was a shorted sub connection so I took them out and checked that everything was going from neg/neg and pos/pos. The subs are connected in parallel. I havent tried a new grounding point yet, but the more and more I think about it, I have to think it is a different issue! I have checked my entire power cable and there is no exposed area, so that rules that out. I will try the new ground point otherwise I will take the voltmeter and see what I come up with.