Amp wont turn on! HELP

[aucky]

This is the current setup i have:

It used to work until i installed the switch, but even with the switch and cooling fans taken out, it still wont turn on..
The fuses on the amp havent gone..
Could it be broken?
(It hasnt really been used, just connected the sub a couple of times to check whilst i fabricate the sub enclosure.. so it hasnt been put under extreem load.)

Can anyone help????????????????
thanks

 

[wallop]

Wow, that sure is a complicated way to wire it up....

 

[aucky]

Wow, that sure is a complicated way to wire it up....

Any suggestions?

 

[wallop]

Assuming the box marked live is a battery & not a fused distribution block;

 

[Rossy197]

Remote wire wired up correctly ?

 

[wallop]

Remote wire wired up correctly ?

If you check first wiring pic he has wired the amp via a switched relay, without knowing this relays rating I would guess it has blown due to excessive current.....

 

[Struggler]

what is the point in the switchable relay in the power wire??

 

[Rossy197]

Forgive me if im wrong.. But i've fitted quite a few amps in my time but from looking at that diagram it looks long winded to me..

shouldnt it be..

1. Power to amp / Power cap
2. Earthed
3. Remote lead
4. RCA's

Job done

So my question is whats with the relay ? And why is it needed

 

[wallop]

Forgive me if im wrong.. But i've fitted quite a few amps in my time but from looking at that diagram it looks long winded to me..

shouldnt it be..

1. Power to amp / Power cap
2. Earthed
3. Remote lead
4. RCA's

Job done

So my question is whats with the relay ? And why is it needed

The relay is required because the remote feed from the Head Unit doesn't carry enough current to drive the cooling fans....

You could simply use the remote feed as a switching supply for the relay, then use the relays output supply to run the fans & act as a remote feed for the amp, but this method has an added risk of induced noise....

You are quite correct in stating the relay isn't really needed, (you could simply run a fused live through a switch & just keep the Head Unit remote for the amp), but I have no idea how the user intends to run his system so have opted to keep a relay in the circuit....

 

[aucky]

The relay is required because the remote feed from the Head Unit doesn't carry enough current to drive the cooling fans....

You could simply use the remote feed as a switching supply for the relay, then use the relays output supply to run the fans & act as a remote feed for the amp, but this method has an added risk of induced noise....

You are quite correct in stating the relay isn't really needed, (you could simply run a fused live through a switch & just keep the Head Unit remote for the amp), but I have no idea how the user intends to run his system so have opted to keep a relay in the circuit....

I think the relays are 30A. I explained the application to the wiz-kid at Maplins and this is what he gave me..

The remote IS used to switch the relay on to power the fans..

The remote switch in the live is so that when my mum borrows the car and doesnt want thumping bass, it can be switched off in the glove compartment.

 

[cliocc]

Yep most likely the relay switching the amp power supply is fubar or the earth for the amp is bad. You don't need the second relay to cut the power supply to the amp (the whole point of the amp remote wire is to turn the amp off when not needed.) Just run the remote wire from the headunit to the glovebox, put an ordinary switch in there then run a second wire from the other side of the switch to the amp and fan relay. This will turn the amp and the fan relay off at the same time, job done. You wont even need the switch in the live power supply as in your or wallop's diagram. Putting in a relay or switch in the live feed for the amp is creating a weak point in the circuit which could heat up and cause you serious problems!

 

[wallop]

With that full explanation of your reasoning behind the switch, I concur with cliocc that the easiest route would be to fit a switch into the remote feed from the Head Unit....

If your actually using two amplifiers in the boot, then run two remote feeds from the Head Unit, then fit the switch into the remote feeding you subs amplifier leaving the remote for your mids & tweets amp intact....

 

[aucky]

With that full explanation of your reasoning behind the switch, I concur with cliocc that the easiest route would be to fit a switch into the remote feed from the Head Unit....

If your actually using two amplifiers in the boot, then run two remote feeds from the Head Unit, then fit the switch into the remote feeding you subs amplifier leaving the remote for your mids & tweets amp intact....

I think i will try the switch in the remote line (no need for a relay).
However i dont think this is the problem, because even without the switch in place the amp seems to have no power...

 

[Dink]

well for a start check the voltage at the amp when you switch the hu on

also check to make sure you haven't blown the amp remote from the hu

 

[aucky]

well for a start check the voltage at the amp when you switch the hu on

also check to make sure you haven't blown the amp remote from the hu

How? put the multimeter accross live and ground on the amp?

 

[Ad172UK]

Sorry haven't read all posts but......

Does it work without relays? ie Remote wire direct from HU to amp?

If so then you may be able to power fans by tapping into Cig lighter??

 

[Dink]

yeah at the amp if it drops(like below 9v) when you fire it up then it's a bad earth

 

[aucky]

Sorry haven't read all posts but......

Does it work without relays? ie Remote wire direct from HU to amp?

If so then you may be able to power fans by tapping into Cig lighter??

No it doesnt..

 

[wallop]

Remove the remote feed from the amplifiers remote terminal....

Using a short length of wire with bare ends, take a feed from the amps +ve terminal to the amps remote terminal....

As you link these two terminals the amp should spring into life....

Does it ???

Using a multimeter check voltage across the amps +ve & -ve terminals, note the result....

Using the multimeter check voltage of the power supply by using the Amps +ve terminal & a point on the chassis, note the result....

Compare the two results above, if they differ, (lower reading using amp terminals), then this indicates a poor amp earth....Similar readings would indicate a fair earth at low draws, in order to check at higher draws you first need to get the amp to switch on....lol...

 

[aucky]

Thanks a lot, I'll get some readings later! =]

 

[aucky]

SORTED!!!!!!
Turns out it was really silly basic faults.

-The in-line fuse (from vibe) was faulty, the end cap at one end is loose and doesnt touch the fuse element all the time. This was giving strange and inconsistant readings. (typically A-Ok when i checked the resistance of the fuse lol)
-The cooling fan relay has 5pins, and the live should have been connected to the centre pin, not the outside (87a, not 87 iirc).

Anyway thanks for all the help guys =]