Able to Use Factory Sub Wiring?

[Inverhyt]

Hey!

So my Ford Explorer 1996 came with the JBL Sound System option, and I was looking to replace the head unit and install a subwoofer in the back of my car. I already have the subwoofer, amp, head unit and mounting kit for all of it but I was curious if I could use the already existing wires in the Ford to the factory amp in the back of the car for the subwoofer to connect to a different amp, or am I going to have to rewire everything?

Thanks for any help or assistance, I will be doing this project in a few days.

 

[J_C]

I don't have the factory amp but do have a reasonable knowledge of audio electronics. You'd want to look at the power wire gauge to determine if it's enough to support the wattage of your new amp. The amp user/installation manual should mention that. This includes the ground wire, if the positive lead is too high a gauge then it probably is too.

I would assume both need a lower wire gauge unless your replacement amp is pretty low power. If you don't need a lot of volume then you might get away with a stiffening cap at the amp, but really going that far, might as well use beefier power wires.

Then there are the audio signal lines and a remote on/mute line. I don't know if "all" JBL system subs had only one voice coil but that may be what you're looking at, that you have only one combined L/R output going to the sub. If you want separate L/R channels and that is the case then you're going to need to run the other channel +/- back to it. That does not have any wattage consideration, but should ideally use shielded cable.

The wire colors for the diagram I'm looking at are:
Dark Green/Violet - On/Mute
Black/Light Green - Ground
Light Green/Purple - Power +
Red/Black - Audio Signal +
Brown/Orange - Audio Signal -

 

[Inverhyt]

I don't have the factory amp but do have a reasonable knowledge of audio electronics. You'd want to look at the power wire gauge to determine if it's enough to support the wattage of your new amp. The amp user/installation manual should mention that. This includes the ground wire, if the positive lead is too high a gauge then it probably is too.

I would assume both need a lower wire gauge unless your replacement amp is pretty low power. If you don't need a lot of volume then you might get away with a stiffening cap at the amp, but really going that far, might as well use beefier power wires.

Then there are the audio signal lines and a remote on/mute line. I don't know if "all" JBL system subs had only one voice coil but that may be what you're looking at, that you have only one combined L/R output going to the sub. If you want separate L/R channels and that is the case then you're going to need to run the other channel +/- back to it. That does not have any wattage consideration, but should ideally use shielded cable.

The wire colors for the diagram I'm looking at are:
Dark Green/Violet - On/Mute
Black/Light Green - Ground
Light Green/Purple - Power +
Red/Black - Audio Signal +
Brown/Orange - Audio Signal -

I'm only replacing it with a 500W amp so I guess we'll see. I'm going to be tearing it apart tomorrow or Wednesday.

 

[Mbrooks420]

I'd run all new wiring. You'll need to run RCA's anyways.

 

[Inverhyt]

I'd run all new wiring. You'll need to run RCA's anyways.

Well crap then. I don't have any of the wires for that atm. I wonder if Car Toys or Stereo King will sell me a kit for cheap.

 

[Mbrooks420]

I'd rather run a cheap Walmart scosche kit than rely on the factory stuff.

 

[J_C]

I'm only replacing it with a 500W amp so I guess we'll see. I'm going to be tearing it apart tomorrow or Wednesday.

500W doesn't seem like much (and many are questionably over-rated) but in terms of 12V current that could still be enough to make lower gauge power wire useful.

Plus, it may be too much current for the fuse on that circuit so you need a separate fused circuit anyway. I'm seeing a 25A fuse on the diagram I have, for both the head unit and amp combined on same circuit, but sometimes fuse rating can vary by model year. 25A * 12V = only ~300W, not considering head unit current nor amp losses since it's rated for output rather than input power.

That alone tells me you can't get 500W out of the amp with the stock fuse, though I am not one who favors hearing loss so I might be inclined to turn the gain down (if it allows this) and have an over-spec amp just for engineering margins and run it at closer to 200W with virtually nill THD, but I may be the rare person who would do this... why give a passenger the ability to crank my radio up to disturbing levels, lol.

Regardless, the short answer is you need to string lower gauge wire and add an appropriate fuse right after the battery.

 

[96eb96]

Hey!

So my Ford Explorer 1996 came with the JBL Sound System option, and I was looking to replace the head unit and install a subwoofer in the back of my car. I already have the subwoofer, amp, head unit and mounting kit for all of it but I was curious if I could use the already existing wires in the Ford to the factory amp in the back of the car for the subwoofer to connect to a different amp, or am I going to have to rewire everything?

Thanks for any help or assistance, I will be doing this project in a few days.

I did the wiring for an aftermarket stereo on this truck. I did it because I wanted a GPS and Android unit, got it very cheap.

The amp cannot be used with any aftermarket stereo. It uses proprietary digital signals from the head unit to the amp. Most of the radio is actually located in the "amp." The antenna plugs in the back. The thing in your dash is just a remote unit and keyboard. The speaker wiring starts at the Amp in the rear of the truck, not in the dash.

You have to run long wires from the front to the back, it is a PITA job. This kit has 20' of wiring: https://www.amazon.com/Metra-70-5601-Wiring-Harness-Bypass/dp/B0002BETAY

You COULD use the subwoofer unit though, with some extra wires. You need voltage to turn it on (maybe tap off the power antenna, or your stereo may have a special line), and you can run wires from the RCA lineouts (not speakers) to that unit. Some stereos may have a subwoofer jack, but you can combine two LR outputs and wire to the sub.

 

[Mbrooks420]

I did the wiring for an aftermarket stereo on this truck. I did it because I wanted a GPS and Android unit, got it very cheap.

The amp cannot be used with any aftermarket stereo. It uses proprietary digital signals from the head unit to the amp. Most of the radio is actually located in the "amp." The antenna plugs in the back. The thing in your dash is just a remote unit and keyboard. The speaker wiring starts at the Amp in the rear of the truck, not in the dash.

You have to run long wires from the front to the back, it is a PITA job. This kit has 20' of wiring: https://www.amazon.com/Metra-70-5601-Wiring-Harness-Bypass/dp/B0002BETAY

You COULD use the subwoofer unit though, with some extra wires. You need voltage to turn it on (maybe tap off the power antenna, or your stereo may have a special line), and you can run wires from the RCA lineouts (not speakers) to that unit. Some stereos may have a subwoofer jack, but you can combine two LR outputs and wire to the sub.

He was just looking to use the wiring, nothing else.

 

[J_C]

I did the wiring for an aftermarket stereo on this truck. I did it because I wanted a GPS and Android unit, got it very cheap.

The amp cannot be used with any aftermarket stereo. It uses proprietary digital signals from the head unit to the amp. Most of the radio is actually located in the "amp." The antenna plugs in the back. The thing in your dash is just a remote unit and keyboard. The speaker wiring starts at the Amp in the rear of the truck, not in the dash.

You have to run long wires from the front to the back, it is a PITA job. This kit has 20' of wiring: https://www.amazon.com/Metra-70-5601-Wiring-Harness-Bypass/dp/B0002BETAY

You COULD use the subwoofer unit though, with some extra wires. You need voltage to turn it on (maybe tap off the power antenna, or your stereo may have a special line), and you can run wires from the RCA lineouts (not speakers) to that unit. Some stereos may have a subwoofer jack, but you can combine two LR outputs and wire to the sub.

That didn't match my diagram so I did some more digging and found two different arrangements based on whether it has just a "high series" stereo where the amp drives all speakers, or the mach stereo where the head unit does (2nd diagram below).

 

[96eb96]

^That is 98+, I see the steering wheel controls. 95-97 premium JBL have a very unique system, shared with Lincolns. It may be unique among all car systems from what I was told. It was quite ahead of its time.

 

[J_C]

^ Hmm, having to rewire all speakers will be a PITA.

 

[96eb96]

^ Hmm, having to rewire all speakers will be a PITA.

Yes. Lots of trim has to come off, the entire passenger side. I went to a local shop looking for a bezel and they said about $500 out the door to do that install. It is not a simple plug and play. A 98 would be a simple $5 adapter, you can also keep your amplifier if you have premium sound.

The kit does not come with the subwoofer wires, so you have to add that if you want to keep the sub.

 

[Mbrooks420]

You would just wire the speakers to the new deck. The factory amp is garbage, and sounds terrible. Pulling the door panels is fairly easy, and anyone could rewire all four in an afternoon.

 

[J_C]

^ It would take me longer than an afternoon because I'd have to keep coming up for air.
(I always hold my breath when pulling ~22 year old plastic paneling.)

 

[Mbrooks420]

A quality panel tool is very helpful, but there's always some cringing involved.

 

[RandomNerd2000]

I've been here, just run a Walmart $25 kit, it comes with EVERYTHING except tools and is a two hour install if you're good with your hands. I put two tens in my 2000 recently, since it was a stock system, and I honestly wouldn't mess with stock audio stuff much when aftermarket blows it out the water.

 

[toypaseo]

I used a Wallymart Scosche 8ga install kit for my Budget Bass project.

I mostly bought it for the 8ga power wire, which was true 8ga. I priced some bulk 8ga power wire at some local car audio places, and it was quite spendy. I also used the RCA cords. Nothing exciting. Zipties were junk. I think most of the crimp connectors were junk, so they pry ended up in the trash.

 

[toypaseo]

(I always hold my breath when pulling ~22 year old plastic paneling.)

A quality panel tool is very helpful, but there's always some cringing involved.

When I was installing in my Explorer, my neighbor loaned me his Snap-On panel popper. Worked great. I dug on eBay and scored my own 3-pc Snap-On set for dirt cheap.

 

[J_C]

I have a panel popper tool, and some spare plastic pop rivets too, but old plastic can still crack or permanently warp, though in some cases I've finessed old plastic trim back into the right shape with a hair dryer.