Sub is not work

[fish32]

hey guys

i installed a new sub the other day and it is not working i bought it of ebay it is a kicker L7 solo baric (old school one) it is supposed to be 750 RMS and im quite sure it is not blown, my amp is like 400 RMS... i would of at least thought i would get some bass out of it.... but it seems when the bass is supposed to kick in the amps light dims right down
can some one help me with my problem

cheers

[HoZy]

disconnect it
throw a multimeter on the sub, an check the impedance.

[acarmody]

Also what Hozy says^^

Where have you grounded the amp too and what gauge wire are you running to the battery? Also have you set the gain properly?

Also what impedance is the sub and what amp model is it?

[fish32]

i had another sub installed to the amp and it worked just fine
also it is 4 ohm

[Jonno]

is the gain set?
is the amp even getting power?
is the remote connected
is it earthing properly

have u got the + & - even connected properly?

[acarmody]

i had another sub installed to the amp and it worked just fine
also it is 4 ohm

As in dual 4-ohm, or dual 2-ohm making 4-ohm. The L7 is a dual voice coil sub. Have you wired both coils up?

[fish32]

dual 4 ohm
and yes i have wired them both
the amp is wired properly because i was running different sub before i put this one in

[sweefu]

What was the gain set at?

[acarmody]

dual 4 ohm
and yes i have wired them both
the amp is wired properly because i was running different sub before i put this one in

OK, cool.

Now what amp model? Also what H/U you running?