Can you disable the dash speakers?

[NeedAStarQuest]

I don't care enough to take the whole dash apart to get to those little fools, 4 MB Quart speakers will work just fine for me...just wondering what wires I need to snip on the harness before I plug in the aftermarket harness to my head unit to disable those front dash speakers..Thanks guys..

[indy_85stariones]

For 87 thru 89 model years, I recommend disconnecting the dash speakers for those that have replaced the door speakers with aftermarket.   For 87 thru 89 model years, the door and dash speakers are wired parallel.  That is, 8 ohm door speakers and 8 ohm dash speakers wired parallel yields 4 ohms of resistance.   Aftermarket speakers are only 4 ohms.  That is, 4 ohm door speaker and 8 ohm dash speaker wired parallel yields 3 ohms of resistance.  Most headunits/amps are stable only down to 4 ohms.  3 ohms is less than 4 -- sooner or later the headunit/amp will burn itself up.  

 

For 83 thru 85 model years, the door and dash speakers are wired in series -- like Christmas tree lights.  If you would disconnect the dash speaker, then the door speaker would stop working as well.  

 

It is not that difficult to unplug the driver's side dash speaker.  Just remove instrument gauge cluster and hood.  You will need to clean or replace the light cluster switches at some point anyhow.   It is removing and replacing the speaker that is very difficult to do.

[NeedAStarQuest]

so I'm guessing since its parrallel that the speaker wires at the harness also feed the door speakers as well as the dash speakers, so I would have to get to each speaker to snip the wires?

[indy_85stariones]

By the time you locate where each wire leaves the harness and runs to each speaker.  It would be easier to just disconnect the connector and wrap in electrical tape.  

 

You snip the wire in the wrong place and you lose both door and dash speakers.  

[NeedAStarQuest]

Can you give me a step by step for disconnecting each side then? Man I didn't know this was going to be so much trouble! I think I understand the driver side..I pop the hood off, and unscrew the gauge cluster and pull it out a bit, and I should be able to see the speaker to disconnect?  I wouldn't have the first idea how to get to the passenger side.  Thanks, Josh

[indy_85stariones]

I have another post/thread somewhere in this forum with step-by-step instructions.  It is titled "Replacing Dash Speakers".  I have bumped it to the top.  

[AzStar]

I have another post/thread somewhere in this forum with step-by-step instructions.  It is titled "Replacing Dash Speakers".  I have bumped it to the top.  

 

Ok.. I'm not an electrical genius.. (er.. I'm not any type come to think of it)

 

So you are saying to 8ohm speakers make a 4ohm?

 

If I replace the factory doors and disco the factory dash.. will I have 4ohm at the door?

 

I would like to put a tweeter arrangement in the door panel (upper) and replace the door speakers.  Also replace the rear speakers.  Probably do an amp with one of those subwoofers that seem to be the rage these days.

 

(I won't tell you how old I am.. but I was driving when the first 8 track stereo players came out)

[indy_85stariones]

Yes, I am saying that a pair of 8 ohm speakers wired parallel yields 4 ohms of resistance at the stereo amplifier.    I have reason to believe that factory dash speakers may be 4 ohms, so the number is really closer to 3 ohms.  

 

Aftermarket speakers are only available in 4 ohms.  A pair of 4 ohm speakers wired parallel yields 2 ohms of resistance at the stereo amplifier.   This will cause the stereo amp to run hot and eventually burn up.  

 

Most people do not take in consideration how critical ohms of resistance is to a stereo amplifier.  For example, take any speaker positive lead wire and accidentally touch any metal in the car.  This grounds the positive lead wire circuit with zero ohms of resistance.  The result is a burnt up stereo amplifier.  

 

Ok, so we know that zero ohms of resistance is bad.  How much is good?  Two ohms of resistance may work for a few weeks, but eventionally reaches the same result -- a burnt up stereo amplifier.    Most stereo amplifiers are stable at 4 ohms of resistance.  Eight ohms of resistance is safe, but you will notice a loss of volume of loudness.  

 

Bringing in Ohm's law of parallel resistance:

http://www.caraudiohelp.com/ohms_law/ohms_law.htm

http://www.installdr.com/TechDocs/999016.pdf

 

1/Rt = 1/R1 + 1/R2 ...

 

The factory speaker system uses 8 ohm speakers

1/Rt = 1/8 + 1/8 = 2/8 = 1/4  

Inverting the equation yields a result of 4 ohms, which is perfectly safe.

 

Replacing with 4 ohm aftermarket speakers

1/Rt = 1/4 + 1/4 = 2/4 = 1/2

Inverting the equation yields a result of 2 ohms, which makes the speaker circuit run too hot -- eventually burning up stereo amplifier.  

 

Bottom line.  

1)  I have not been able to find nice aftermarket 8 ohm speakers.  They seem to be only available in 4 ohms.  

 

2) Keep it simple.  For 86-89 model years, install nice 4 ohm aftermarket speakers in the doors and unplug the connectors to the speakers in the dash.   Better yet, run new thicker wires to the doors.  

 

Your solution.  

Purchase component speakers for the door -- one tweeter, one regular speaker (woofer), and one crossover box.   The crossover box manages the workload, so you don't need to worry about ohms.  

 

You can mount the crossovers two ways.

1) one mounted in each door

2) one mounted on each side of stereo amplifier.

[AzStar]

We installed a stereo in one of my son's Starions couple months back.  Didn't disco the dash speakers tho.  He sold the car but I will tell him to inform the person we sold it to.

 

The door speakers and tweeters came as a "kit" and had the crossover box included.   Mounted very nicely in the door with no problems.  Same type of setup I would like to do with mine when the money become available.