QuestionQUESTION: I have a 1994 Jeep Grand Cherokee with the infinity amp under the seat and I put a boss headunit to put in it well the amp in the boss headunit is blown so I figured that it would still work with my stock amp. So I bought the adapter plug for the radio and hooked it up and everything works but it is quite. I thought about getting an amp for the speakers just so it would be louder. do think there is a problem and what do you think I should do?
ANSWER: Hi Paul,
The factory Infinity system in the Grand Cherokee works with high-level signals going to the amplifier; in other words, it's meant to use speaker outputs from the head unit, not low-level RCA outputs. If you've wired your deck's RCA outputs to the factory amp, then you won't get much volume. You can install an after-market 4-channel amp in place of the factory Infinity amplifier; this will be designed to work with RCA outputs, so it should get much louder. Or, you can replace your head unit with one that has working speaker outputs. This will work better with the factory amp.
Hope this helps!
Brian
---------- FOLLOW-UP ----------
QUESTION: I have a 1994 Jeep Grand Cherokee with the infinity amp under the seat and i bought another headunit and i would like to know how you bypass the amp or run the speaker outputs staight to the headunit or even speaker outputs to the amp. thanks.
AnswerHi Paul,
If you use a standard Chrysler wire harness to connect the new head unit to the factory radio plugs, then you'll be connecting the head unit's speaker outputs to the factory amplifier's high level inputs. In this case, all you need to do is connect the factory amp turn-on wire (the blue wire in the adapter harness) to get the system working with the new head unit. This is recommended if you're keeping the stock speakers in place.
If the original radio plugs are no longer present, you can connect directly to the stock wires. Here's the color code:
Constant 12VDC: red/white
Switched 12VDC: red/gray
Amp turn-on: dark green/red
Ground: black (originally connected to stock head unit chassis)
Illumination: dark blue/red
Dimmer: orange
Speaker outputs to factory amp:
Left front (+): dark green
Left front (-): brown/red
Right front (+): violet/yellow
Right front (-): dark blue
Left rear (+): brown/yellow
Left rear (-): brown/light blue
Right rear (+): dark blue/white
Right rear (-): dark blue/pink
If you need to bypass the amplifier, you can do this at the amp location. To bypass the amp, you need to identify each input wire (same as the speaker output wires from the head unit, listed above) and connect it to the respective amplifier output wire going to the speaker. Here's a list of the output wire colors at the amplifier:
Left front (+): light green/red
Left front (-): light green/black
Right front (+): light blue/red
Right front (-): light blue/black
Left rear (+): white/red
Left rear (-): white/black
Right rear (+): tan/red
Right rear (-): tan/black
So, to bypass the amp, you'd unplug it, then connect each speaker input wire directly to the matching speaker output wire in the amplifier plugs. When you're done, each speaker will be connected directly to the head unit's outputs through the factory wiring. (The front door speaker and dash tweeter on each side are wired to the same output at the amplifier).
Hope this helps!
Brian
