What size inline fuse?

[jht3]

Ok, maybe this is a dumb question but I can't find the answer anywhere. I know i knew the answer at one point, but i'm getting old

My 4ch amplifier has a 30amp fuse in it and i'm putting a fuse on the power wire, but I don't know what amp rating to put in. I am ready to throw a 20amp fuse in the holder so it'll pop before my amp fuse will. Is my thinking correct?

[808BMW]

Fuse rating is based on wire size. What size wire are you using?

In my opinion, using the same fuse rating on your wire as the one on your amp is fine. If your fuse is too big for your wire, then your wire is too small for your amp :P

I would guess, but that amp sounds small... my sub amp uses a 200A fuse :P

[jht3]

it's an old a/d/s pq10.2 amp. i'm running 4ga from the battery to the fuse block, then 8ga to the amp.

so i get my whole car wired up and go to test out my new system......nothing. headunit powers up like before but the speakers remain quiet. fawk me

in the trunk i have my amp and 2 crossovers. i ran 3 sets of interconnects forwards, 4 16ga speaker wires (2 for the mids, 2 for the tweeters), and the remote on lead. i tested each speaker wire in the trunk w/ a 1.5v battery and heard each front speaker "pop". remote lead shows ~12v at the amp. 8ga power lead shows 12v too, and the ground checks out as well (there isn't an LED on the amp to show its powered up). i did pull the onboard fuse and am seeing 12v across the pins. i tried testing for voltage at the rca ends, but couldn't get a reading. i put the red lead on the tip, and the black on the ring.....0.0v. now i shoulda marked each lead b/c i have 3 sets of rcas in the trunk and don't know which is the front, rear, and sub (not planning on a sub or rears just yet). it's possible i goofed on something small, but i'm fairly confident all is hooked up correctly. it was getting dark and threatening rain so i had to call it a night

so my question is, am i checking the rca's correctly? i thought i'd see some low voltages on each rca. it's a nakamichi cd-45z headunit btw.

[92 mtechnic cabrio]

are your amps indicating that they are being powered?

[StereoInstaller1]

RCA voltage will be AC, not DC. Use a walkman or other portable as a source to test to see if it is amp or deck not working.

Oh, and use a fuse about 20% to 50% bigger than the amps fuse at the battery. The battery fuse is to protect the WIRE, not the amp.

Luke

[jht3]

are your amps indicating that they are being powered?

my amp doesn't have an indicator light. it is getting power and a good ground.

RCA voltage will be AC, not DC. Use a walkman or other portable as a source to test to see if it is amp or deck not working.

Oh, and use a fuse about 20% to 50% bigger than the amps fuse at the battery. The battery fuse is to protect the WIRE, not the amp.

ahhh...ac. i need to dig my boombox out of storage and to test the speaker wiring (including the crossovers this time) and provide a source to the amp.


i'll get to the bottom of it once i get some more time, but it's frustrating it didn't work right out of the gate. i took my time getting it just right....or so i thought

[jht3]

well i tested all my wires with my boom box and multimeter

-the wires to the speakers are good, i hear music when connecting the speaker wires to the output on the boombox

-the rca outs from the headunit are working. i have music on all three sets. i figured out which was the rear by fading everything to the front, but can't distinguish between front and sub....help?

-the power and remote-on are both showing roughly 12v, and the ground checks out (tested between the amp end and the ground bolt behind the rear seat cushion).

-i get nothing from the amp. it's getting power but it remains silent. blown? it is old. when i tried jiggling the ground wire screwed into the amp, i blew the 60amp fuse on my power wire. the 30amp on the amp itself remains intact.


so looks like i need a new 4ch amp huh? is it possible to get my amp benchtested? what sucks is i gave a buddy an old WORKING 4ch amp last year. argh

[DSchultz325e]

well i tested all my wires with my boom box and multimeter

-the wires to the speakers are good, i hear music when connecting the speaker wires to the output on the boombox

-the rca outs from the headunit are working. i have music on all three sets. i figured out which was the rear by fading everything to the front, but can't distinguish between front and sub....help?

-the power and remote-on are both showing roughly 12v, and the ground checks out (tested between the amp end and the ground bolt behind the rear seat cushion).

-i get nothing from the amp. it's getting power but it remains silent. blown? it is old. when i tried jiggling the ground wire screwed into the amp, i blew the 60amp fuse on my power wire. the 30amp on the amp itself remains intact.


so looks like i need a new 4ch amp huh? is it possible to get my amp benchtested? what sucks is i gave a buddy an old WORKING 4ch amp last year. argh

You can just run a multimeter on the speaker output terminals and test for voltage.

[jht3]

You can just run a multimeter on the speaker output terminals and test for voltage.

what test are you referring to?

[DSchultz325e]

Hook the probes up to the speaker outputs and set it to AC voltage? Voltage = signal, no voltage = no signal.

[jht3]

i assume you're referring to the speaker outputs on the amplifier. i'm not getting anything on those outputs.

what worries me is i keep blowing the fuse on the power wire. i'm running 4ga from the battery to the fuse block, then 8ga to the amp. 8ga ground wire is maybe 6" long and screwed right into the sheet metal behind the rear seat. i used my dremel to grind away all paint and sound deadening, and my multimeter shows a good ground. my amp has these little connections for the power and ground wires, the only size i could actually fit in there might be 14ga. so i'm using these screw on pin connectors to hook it all up. they dont seem to provide the most solid connection, but i dont see any other way to do it.

[StereoInstaller1]

what worries me is i keep blowing the fuse on the power wire.

End of question. Dead amp. Usually more to repair than replace. If you want Exile or Memphis, you get the R3V deal from me.

Bummer deal on the old ADS though. Sweet amps in their day.

Luke
Loud & Clear
541-747-1171

[jht3]

End of question. Dead amp. Usually more to repair than replace. If you want Exile or Memphis, you get the R3V deal from me.

Bummer deal on the old ADS though. Sweet amps in their day.

Luke
Loud & Clear
541-747-1171

craaaap. really it's more to repair than replace? that totally sucks. everything these days is disposable.


i know nothing about exile, memphis, or any other amps really. i'm looking to power my mb quart components in front and just the stock mids in the back (for a little extra fill). no sub planned yet, but if i do go that route, it'll be something small like an 8 or 10".

so basically i'm looking at a 75x4ch amp. i suppose i could also run new speaker wire all the way back from the headunit for the rear speakers, but if i do ever decide to run a sub, it would do that then, and bridge the two now unused channels and power the sub that way.

[StereoInstaller1]

How about a real 35X4? That will likely be overkill...convert the rear to 6X9's, or the Memphis 8" 2 ways, run the Quarts in high pass.

Anyway, PM or call if you want a price.

Luke