How do you connect an amplifier to factory stereo?

Likely you will have to replace the radio. If it is amplified at factory, your best bet is to replace that as well since most factory amplifiers are not compatible with aftermarket stereos.

There isn't any reference to an amplifier added to the factory stereo, so it is internally amped. Later model Sonatas (2011 and up) with premium audio do have amplifiers factory fitted (located in the trunk space on the right side behind the trunk liner).

Mercury Mountaineer 2002 2005 Factory Service SHop repair manual Download

for the easy solution download the pdf file

Only if the factory stereo has an aux input can you connect the two.
Now, if the stereo has a tape deck, you can buy an adapter that plugs into the tablet (or other device) then you put this cassette looking thing into the player and it works.

First off, is this a factory stereo or an after market? If this is an after market did the problems start then? If so, who installed it, you, a friend or a professional. If this was before the stereo then I would look at what is called the body computer. This causes low voltage nightmares. Let me know if this does revolve around the stereo/amplifier and we will go form there.

if the car has a factory amplifier he didnt connect the remote wire from his aftermarket stereo to power the factory amplifier

I had the same problem when I changed out the factory cd player. I finally found the problem was that grand am gt cars have a couple of amplifiers with crossovers in them for the speakers and the after market stereos put out sound that has been slightly amplified already and when you hook up your new stereo to the wiring harness your sending amplified sound from your stereo the the factory amp then to the speakers this sometimes messes with he sound and clarity of the sound. My car is 2002 and the factory amps are located 1 under the glove box and 2 in the trunk behind the carpet on the drivers side. The amp and crossover in the front is to split the signal for the door speaker and the tweeter by the mirror and the amp in the trunk is to split the signal for the two way speaker in the back by the back window witch if they are like my factory speakers have 2 wiring harnesses connected to each speaker. the only way I could get mine to sound good was to run new wires from your stereo directly to the speakers and bypass the factory amps. This may not be the only way to fix this issue but it was the only way I could figure it out. I hope this helps

Metra Part# 70-8113

This is the only part you will require to retain factory amplifier when you switch to an aftermarket radio.

Best Buy does not use Metra Products.

They use cheap American International.


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You will require an adapter for your amplifier.
It will look like this...

One end will accept your factory antenna plug, and the other is a MALE standardized size to fit aftermarket products.

METRA makes one, and the part # is 40-EU55

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i had the same problem and found out that i bought the wrong harness. there are two styles one for non-amplified and factory amplified.