Factory amp not turning on

[Dallas99XLT5.0]

Just purchased a '99 XLT 5.0 with 117,00 in excellent condition. I noticed that the factory rear sub was not working. Pulled the panel and tested for power to the factory amp. The largest wire in the factory plug is a constant 12v. I was reading on this forum and some stated that the amp trigger wire is powered by a 5volt signal not the traditional 12v trigger on a aftermarket head unit. I am assuming that the signal comes from the factory head unit. Tested the 4 other wires with ignition on and off and No voltage. Wires are not pinched. I Removed factory head unit and found no indication that head unit has ever been out or wires and or plugs were disconnected. Checked all fuses on both fuse boxes. Is this a problem with the factory head unit? Thanks!!!

 

[BBBB51]

My daughters 98 has a off on switch for that amp where the rear passengers could use it on the end of the center consol. no grammer nazi,s pls

 

[Wray-Wray]

I don't know of a factory sub set up on the 99's correct me if there is please......

so


assuming this is an aftermarket set up(head unit, amp and sub).............

The large wire is 12v is your power supply

The trigger wire(5v) you refer too i believe is your remote
- make sure you only get this power when the key is in the on position
- examine the amp for a protection light.....if its on(when the key is on) then the amp is hooked up wrong and will not work

As for the other wires you should have a
- ground wire (if the ground wire is not grounded correctly the protection light will be on and the amp will not work)

- RCA cables(if your RC cables have no voltage going threw them the subwoffer will not play check for pintches in the wire from like putting the rear seats up in down or under the plastic strip next to the door)

- and speaker wire(if these wires are kinked in any way the sub will not play check them as well)

as for the head unit

- If the RCA output jacks are messed up in some way then the RCA cables will have no current or voltage and will not tell the amp what to do so the sub will not work

- check for something stupid like the bass for the sub being turned down in the equalizer settings on the head unit

AS for the amp itself

check the settings on the amp

- if the bass power dial or switch is turned down all the way the sub will not play


for the box

- check the box see if the wiring is connected from the terminals insde the box to the sub.......


and for the sub

- if itz blown it pay not play all together(has happend to me personally)......i would remove it from the box and take it to a custom auto sound place and have it tested...i would do this last because everything else you can do for free(if you are handy with wiring).....getting the sub checked may cost you some money.........it may not you haft to ask them.....




............off the top of my head thats what i think.........you should check....hope this helps man good luck!

if you have any other questions let me know!