MAFFA

Dunno what's going on? I've got a set of components in the front powered by the headunit, an amp taking power from the battery which powers my 10" sub & power looped from that to another amp that powers the 6x9's on the rear shelf.

The other day the fuse went in the amp powering the sub & I thought nothing of it & replaced it. Within 10 seconds that fuse had gone!! Okay I thought...knackered fuse, so I replaced it again. This time after about 10 seconds the fuse in the amp basically melted & so did the one in the power lead coming from the battery I had to pul them out with pliers as they'd almost jammed themselves in!!

Just been and had a look and nothing seems to have changed. The earths are still earthed and the second amp is working fine off the looped power

Any ideas?

MAFFA

Ian

iTrader: (10)

check the power wire, and that it hasnt been cort/broken and shorting out somewhere

MAFFA

If it had would it not affect the second amp using the same power source?

MAFFA

grey-wrx

How have you checked the earth? usually fuse blowing is down to a poor contact

scoobnoob05

If i understand the way you have wired the power cable

Daisy chaining the amps power cable is not a good idea mate

as far as the main power cable is concerned, it will only 'see' one amp and supply upto its fuse rating for that one amp before blowing. The problem is that the power for the second amp is also passing thru the terminals of the first amp, which is why the fuse blows.

as an example if amp one has 30amp fuse and draws say 25amps then amp two that is also connected to amp one draws more than 5 amps the fuse in the first amp will blow cos its overloaded. Basically the first amp is acting like a distribution block which its fuses will not like

each amp should have its own power cable feed (splitter in main cable)

hope that helps


J

ScoobyDoo69

iTrader: (17)

as said above it sounds as if you've got the power routed wrong. You should preferably have the main power cable coming from the battery, and then splitting into 2 via a distribution block which have a seperate fuse for each split. and again the same thing should be applied to the earth.

Regards

SD69

ru'

Assuming the first fuse which went was the one in/on the amp itself (and not in-line with the amp's power lead) then it sounds like the amp has had it I'm afraid.


Assuming you have enough fuses, you could just rig it up on its own with some cables to the battery and see if the fuse still blows - try and use a smaller fuse, say 5 or 10 amps or so (and make sure you have thick cables to test it with - you want the fuse to blow, not the cables!).

For safety's sake, it's worth keeping the amp away from the battery so as not to ignite any fumes which 'could' be present (very unlikely) so use wires which are long enough.

As you aren't running audio through the amp the lower value fuse should be enough to just power it on (you may need to connect the remote power on terminal to the +ve one to get it to turn on).

As you've run dedicated 'test' power cables it will remove any doubt about the installed cables too.

MAFFA

Cheers for the advice guys Time to run a couple more test I believe. Funny though as i've been running this set up for the last 2yrs or so and never blown a fuse Maybe it's time to split the power feed

MAFFA

teknobod

Could be a faulty speaker which has stuffed the amp. Check the speakers out before connecting them to a new amp.

Andy

ru'

Although splitting as described above is the best way to do it, whether you 'need' to or not depends on where the first amp's fuse is.

If it's in/on the amp itself (not in-line with the power cable) then it's not so important to have a separate splitter - daisy-chaining off the first amp's power terminals will be okay. As you say, you've been running this for two years.

Kinda hard to explain, but this is how I guess you have it:

Battery - Main Fuse - Power Wire - Amp1 Terminals - Power Wire - Amp2 Terminals (with the fuse on/in the Amps).

This is okay, but this isn't:

Battery - Main Fuse - Power lead - Amp1 Fuse - Power lead - Amp1 Terminals - Power Lead - Amp2 Terminals.

Hope that makes some sense!

ps my suggestion above for testing shouldn't need 'speakers/HU connected at all.

MAFFA

Ru - got it spot on with the first description which is why i'm thinking the amp has lunched itself This is because if it was the power supply then the second amp fuse should go as well being as the power is only looping from the terminal so is in effect a direct power source to the second amp...if that makes sense?

The main fuse in the power cable is fine as long as the fuse from the first amp is out and so the second amp keeps working. It only blows when the amp (Internal) fuse blows.

MAFFA