Audio Systems: testing cont., voltage on circuit, car fuses, power cap

Question
For a regualr auto do you have to disconnect the battery to check fuse continuity, and for voltage do you have to turn on acc/ignition?

Also when adding additional op amps, capictors, to the audo system (stock) will you have to add more current to the circuit or the whole electrical system?

Answer
Fuse check is best done by pulling it out and put it on the Ohmmeter check of your VOM.  But, usually, they are visibly observed. The fuse element is generally large enough that you can see when it has opened up.  Most car fuses have the fuse element visible.  Of course, you can check with the voltmeter on each end of the fuse (with radio ON), but it doesn't always give reliable results.

Adding additional amps and "stuff" you should determine the output rating of the current generator/alternator and increase the system if needed.  But,if you are adding a big amp you will no doubt need to put in a high output generator and maybe a new high capacity battery.  Adding power cap can help somewhat, but their purpose is mainly to increase bass frequency output power.

Hope this helps; let me know if you have more questions.