Amplifier for 1997 Expedition Premium Sound

[367KIX]

The radio has been dead on my X for some time, including no clock on the display when its turned off. I do hear some possible relay clicks under the hood with the ignition switch turned to accessory. Triple checked fuses and am sure power/fuses is not the issue, at least for the head unit. I finally purchaced a new JVC head unit and wired it up. The new stereo lights up very pretty, but no sound through the speaker system. I've verifed with a test speaker that the new unit is producing audio, so I'm assuming the original head unit and/or amplifier are broken, preventing audio from getting to the speakers.

I've looked through the other threads and haven't seen anything specifically about which 97 Expedition configurations have a "hidden" amplifier. Mine says "Premium" on the front two speakers, but it seems to be a regular four speaker system, with no guarantee of a hidden amp some place. With the head unit out, I did see down lower, behind the dash, what looks like the heat sinks for what I think might be an amp, but I can't verify its an amp via wiring traces without tearing out the dash.

Any suggestions or experiences on if this car should have an amp and if what I described is an amp for sure, would be appreciated. It looks like I'm out of luck on fixing the tunes, except for an amp replacement (if needed) or rewiring to the speakers to bypass it altogether.

 

[BOOTLEG]

Hi there , usually when it says it has a PREMIUM SOUND SYSTEM it means that there is an amp on the driver side close to the third row seating, but then again mine is a 04 so i could be wrong.

 

[tonydiv]

It may not be what you want to hear, but you're probably better off just running new wire directly to the speakers. It will most likely take less time than trying to hunt down the factory wires and then tapping in to them.

It's also a good time to upgrade to better speakers.

 

[367KIX]

Thanks for the suggestions. I did see in another Ford forum that there is definitely an amp, but I'll have to see if it's in the same place as the newer model. I can't find a wiring diagram yet, which would help, if I decide to bypass them, around the amp. And rewiring to the (new?) speakers is a workable idea too.

 

[bubbadabulldawg]

There should be a harness available to bypass the factory premium amp in the quarter panel. I did that for my wife's exploder when I installed a new stereo with bigger amps and a sub but used the premium factory speakers. Here is the Metra harness to bypass the amp Metra Electronics Corp. - 70-5605

© COPYRIGHT 2008
EIA COLOR CODE
COLOR FUNCTION
RED ACCESSORY
YELLOW BATTETRY
BLACK GROUND
BLUE POWER ANTENNA
BLUE/WHITE AMPLIFIER TURN ON
ORANGE ILLUMINATION
ORANGE/WHITE DIMMER
GRAY RIGHT FRONT +
GRAY/BLACK RIGHT FRONT -
WHITE LEFT FRONT +
WHITE/BLACK LEFT FRONT -
VIOLET RIGHT REAR +
VIOLET/BLACK RIGHT REAR -
GREEN LEFT REAR +
GREEN/BLACK LEFT REAR

 

[airhoag]

I have a 97 and I just went through this about a week ago. Since you have the Premium Sound, you do have an amp. If the amp is working, all you have to do is turn it on. Assuming you bought a harness to connect your new head unit, you just connect the Blue/White (Amp turn on wire) from your head unit to the Blue/White wire in the harness. That should do it for you. If the amp isn't working, then you will need to buy the amp bypass harness.

 

[367KIX]

Thanks for the great recommendations. Powering up the amp seems so obvious now, but you know how that goes. I'll go for the bypass if that doesn't work. BTW, I did see that the original stereo head unit had one or two breaks on the bottom circuit board, on the back corner. I'm speculating there might be a 'watch type' battery on the back of the head unit (for data retention?), which looks like it leaked down on board and ate some copper. I likely won't bother with attempting a repair, as there is nothing that desireable about AM/FM/cassette entertainment.

 

[airhoag]

I know exactly how that goes. As a matter of fact, the guy at the stereo store suggested it to me and I had that, "Oh yeah, duh" feeling. I hope it works for you. Mine is all in and working great. Now to replace the factory speakers. Maybe for Christmas.

 

[tonydiv]

Where exactly is the amp located? (mine has rear heat/ac)

 

[airhoag]

I have a 97 with rear air and it is behind the dash on the firewall. Wen I removed the stereo, you could look in and see it down in there a little bit. I'm not sure if it's the same for the 98.