need help with stereo, tricky wiring head unit

So, ive been searching for answers all day, i took my car to a reputable audio dealer, and they told me that either my "factory amplifier" is fried, or my speakers are all blown out ( yeah right). I have found mixed replies about wether 91 240's have factory amps, and one guy with the same problem as me (head unit powers on, and counts tracks and minutes, but nothing comes out the speakers) said he had to hook one of the random wires (blue with white stripe) to the main power to make the sound come out the speakers. The wiring diagram i had said the blue/white wire was for a speaker. My stereo now randomly comes on, like once in 10 starts, sound will come out the speakers, but there is this humming and clicking coming through the speakers that follows my engine rpm, ive grounded it multiple times, and same problem. If this is comon with factory-to-aftermarket head unit swaps, a quick fix would be great.

thanks in advance
cj

i had the same prob. u can do it one of two ways. first way get new wires an speakers. second way is when u go to hook up ur front speakers run some speaker wire to ur door speakers, and just plug them straight into the head unit, an do the same for the back speakers. it works fine, just hide the wires and nobody knows the diff. sept u. plus i find that the tunes come out cleaner this way. then again maybe as i keep sayin, im jus crazy

where did you try grounding it?? and what gauge wires are you using?? if i were you, i'd go to best buy and get their wiring kits. that way you can basically start over and make sure all your wiring is right.. try a lower gauge wire, you'll get maximum current flow.. and for the power, make sure the big yellow wire (power) is in good condition.. if not then i'd say the deck is fried..

yeah i agree. take apart and start from scratch with new wiring harnesses unless you have a factory amplifier outside the factory deck. and as your putting it all back together. test each speaker individually....

if you have factory external amplifiers, your gonna have to rewire the whole car with new speakers and wires(9 times out of 10) because usually old Bose systems have bad wires running wrong ohms which causes the amps and speakers to fry....and the bose speakers do not work properly without the bose amplifier.

good luck...

ty for all the help guys, ill try rewiring the system