Ford Focus Audio Problems

[skateskoot9]

I have a 2001 Ford Focus ZX3 and a couple years ago I decided to start a basic car audio system. But this year I have had quite a few problems. Over the winter my fuse blew on my power wire but was not much of a big deal.But now I am confused on what or where my problem is now. I am getting power to my amp but there is no sound coming from my solo 12" sub. I have replaced the amp thinking maybe I blew that but still the same problem continued. Earlier today I replaced the 12" sub but still the problem continued. I have checked all the wiring coming from the head unit and found no problem.

If anybody could help, please write back.

Thanks.

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[kross 10+ year member]

Do you have a multimeter? If so, there are a few things you can check.

Disconnect your sub from the amp, and measure its resistance. It should be somewhere in the 4 ohm vacinity. Maybe a little higher, maybe a little lower. What you don't want to see is an open circuit, meaning infinite resistance, or a short, meaning 0 ohms.

If that checks out, set your meter to measure AC, and check the output of the amp while music is playing. The number you see will depend on the volume of music, and the gains on the amp. But it should be somewhere between a couple volts and a couple dozen volts.

If that checks out, then that would be weird, but I would suspect the sub at that point.

If you're NOT getting any signal on the output of the amp, then we can check to make sure it's getting a signal from the RCA's. Unplug the RCA's, and check the voltage on them, again with your meter on AC, with music playing. You should see something from anywhere between .2 and 2 volts, maybe even a little higher.

If you're getting signal on the RCA's, but no output from the amp, switch your meter to DC, and measure the supply voltage to the amp. It should be between 12 and 15 volts. Also, measure the voltage at the remote turn-on lead, it should also be between 12 and 15 volts.

Hope this helps!

-- Kevin

 

[skateskoot9]

Thanks for the advice I checked out my amp with the multimeter and im pretty sure I have an open circuit. the meter just went straight to 0 ohms when I tested. What does that mean? And how could I fix it?

 

[kross 10+ year member]

When you say you checked out your amp and got 0 ohms, what did you measure, exactly? You shouldn't be measuring resistance on anything on the amp. Only the sub.

And 0 ohms means a short, not an open circuit.

 

[kross 10+ year member]

I just re-read my first post, and realized it's kind of ambiguous:

Disconnect your sub from the amp, and measure its resistance

When I say measure its resistance, I meant the resistance of the sub, not the amp.

 

[skateskoot9]

I disconnected the sub from the amp and tested the + and - speaker wire that was connected to the box. Should I be testing something else?

 

[kross 10+ year member]

No that's good. But 0 ohms isn't good. Is it a digital or analog meter? Is it set for autorange? If it's digital, and the range is manually set for a high range, it will round 4 ohms down to 0, giving you the false impression that there's a short. Use autorange if it has it.

 

[kross 10+ year member]

Anyway, if you're sure it really is 0 ohms, then you have a short somewhere. Either the wiring, or the sub itself. You'll probably have to take the sub out of the box to check it out.

BTW, is this a 4-ohm sub? 2 ohm DVC? Or something else?

 

[skateskoot9]

The multimeter is analog. The sub is 4-ohm. Would you recommend replacing certain wires, or what should I try fixing or replacing to fix this problem?

 

[kross 10+ year member]

Just to be sure, since you have an analog meter, you can tell the difference between 4 ohms and 0 ohms? On some, it's hard to tell. 4 ohms would be perfect, 0 ohms would be bad.

Anyway, if it really is 0 ohms, then you need to look for a short somewhere. If you can't find one outside the box, then you'll have to look inside.

Also, just as an extra check, when the sub is disconnected from the amp, and you play music, and you set your meter to measure AC, do you get anything when you measure the output of the amp? If you do, then this is a good double-check to make sure the problem really is the sub.

 

[skateskoot9]

Are there any signs I should look for when trying to find a short?

 

[kross 10+ year member]

Before you start taking your sub apart and looking for wires touching each other, it would probably be easier to check the output of your amp, to make sure it's actually outputting a signal.