Headunit Install.....HELP!

[evoq007]

Well i got my new HU, and all the stuff that i needed to install it. Sounddomain.com sent me the wrong HU harness....i have the one big grey plug and then the smaller square black one. so i went down to tweeter and bought the "proper" harness...and it fit in perfectly with the square one. so i hooked up everything according to the labels on the wires....and tried it out...NO sound out of any speakers. so i hooked up just a plain speaker to the HU, and sound came out. so i was able to cross out the HU as the bad part. Can anyone guide me here! lol need help please

thanks boys

Scott

 

[Alec]

Did you get an amp bypass harness, or just an adapter harness?

You probably need an amp bypass harness.

 

[Heath]

Actually your problem is probably that you didn't bypass the stock amp in the rear... Thats another harness that you need... Either that your you'll need to run new wire from the HU (or aftermarket amps) directly to the speakers...

 

[XplorerKid]

you prolly have the amp in the back passenger comprtment messing you up, you'll need a amp- by pass plug

PEACe

 

[Alec]

too slow

 

[Heath]

Damn you Alec...

 

[evoq007]

are u sure, cuz i dont have the premium audio...how will it bypass the stock amp?....i dont have to go put it in, in the rear...does it plug right into the back of the HU


Scott

 

[Heath]

It plugs in the rear... Some you have to run wires back to the front too...

 

[evoq007]

how hard is it to get to the rear....cuz i have the explorer sport....how long do u think it might take?...should i just have tweeter do it...thanks

Scott

 

[Alec]

Took me about 2 hours to do it with my dad's help. You'll need a Torx 50? bit to undo the rear seatbelt anchor.

 

[evoq007]

oh boy, looks like i have a fun day tomorrow....i hope tweeter has a amp bypass harness....anyways...thx guys

Scott

 

[Alec]

If not, Crutchfield has them and they send you very complete instructions.

 

[Kustom Toyz]

I have had the same problem. Even though you probauly already sovled the problem, heres how to go about it. Theres a blue remote ant. wire that acctual controls the factory stock amp in the rear. I had a hell of a time with it. But ifyou dont beleive me try it for yourself. Take a mutimeter and connect the blue wire to one lead and the other lead to gound. When the ignaton is onyou will get 12v. Whn you turn the ignation off you wont get 12v. Me home stereo shop didnt even know about it.

 

[evoq007]

ya thats exactly what i did, so now im just overpowering the stock amp...ill get a bypass sometime...thanks guys

 

[Pete]

Dumb question: why would he need an amp bypass at all? The factory amp is made to work with a factory HU. The factory HU makes speaker-level signal output that goes to the factory amp. The factory amp is looking for a speaker-level input, not a line-level input (unless I'm wrong). The new HU would have exactly the same output level from it, i.e. speaker level, not line level. My '91 has no device in the wiring between the HU and the amp, according to the wiring diagram in the EVTM manual. I don't get it? Pete

 

[Heath]

The new deck will put out probably at least 4 times the power of the old one... Its not just a signal...

 

[Pete]

OK forget the term 'signal' - how about 'complex waveform' instead . The fact remains that the 'stuff' coming out the new HU output terminals is still not fundamentally any different than the 'stuff' that came out of the factory HU, so the factory amp should accept it with no problem. I know this because Ford uses the same HU in standard and premium sound systems and the standard sound system has only factory speakers and no power amp.

The factory unit was either a 15Wx4 or a 25Wx4 RMS (not peak) depending on the year of the Ex. The new HU is not likely much more than 25Wx4 RMS. Even if it is, at low volume levels it is still a speaker-level signal (much higher voltage than line level). My question still stands. The factory amp should still accept that signal with no problems. I am obviously missing something here.