mhora

alright my 94 LS has a factory sub and it cuts in and out it works but only occasionally what would cause this and what do I have to do to get it to work

RA40

iTrader: (6)

Check the wiring from amp to sub, head unit to amp.

mhora

Ok.. next stupid question. Where the hell is the amp at?

Schramm

The problem is likely caused by a worn potentiometer used for bass control on the head unit. They can wear out. Does the bass control **** feel smooth or gritty/loose when turned? If it is not smooth and the bass cuts in/out when turning it, the contact points are likely worn and have intermittent resistance. You can take it apart and test resistance with a meter. You may be able to swap parts from a head unit that is in better condition, but that is hit or miss. The controls are on a separate circuit with small connector. Or find a new replacement part based on orig. specs. and solder it in. If its a Pioneer, you may be able to source the part from them with the service manual to identify part number. If Nakamichi, parts no longer available - you may need to order from electronics supplier like Digikey or Mouser. There are a few places that will service these units if you are not DIY, but it is expensive.

Also, you can disconnect the subwoofer connector and test it individually. It would be very rare, but a speaker's voicecoil can have an intermittent open circuit scenario, when it heats up and expands. The amp can have problems too, but it is not as likely to be the cause.

Have you removed the subwoofer grille cover on the parcel shelf to inspect the subwoofer condition? Is the surround in good shape?

RugbyDad

Under passenger seat. Move seat all the way forward and you should be able to see it.

AzHotLS

iTrader: (1)

+1

One possibility is that the foam has separated from the cone. Some have had good luck gluing it back together.

mhora

It has an aftermarket head unit in it... and it is using the RCA harness

timmy0tool

iTrader: (7)

aftermarket headunit means the factory wiring was hacked into or altered in some way. check the connections behind the headunit first, then check the amp and sub. it is also possible the actual sub is dying.

mhora

The wiring was not hacked or altered it was installed using a harness thay plugged into the original harness. And the sub is new. Along with all of the speakers.

msweber97

can you post a pic of the harness that was used to plug into the factory harness, im trying to figure out what i need to do to get my factory sub to work with my aftermarket stereo

timmy0tool

iTrader: (7)

to make the factory sub work correctly you will need the beatsonic box: http://www.beatsonicusa.com/beat-sonic-sla-20ad.html

more info here:
https://www.clublexus.com/forums/ls4...up-thread.html

as explained here, using those metra wiring harnesses does NOT enable the factory subwoofer.
http://www.lexls.com/tutorials/audio/headunit.html