Front door speakers not working (Mach 460)

[brtnstrns]

I posted this in the sound forum but apparently no one ever looks at those because I've gotten no responses. Does anyone know where I should start looking if my door speakers, which I believe are subs, are not putting out any sound? I've looked at both amps in the back and there isn't anything unplugged or any funky wiring done. Is there a fuse solely for those speakers that I may need to replace or any other ideas on what the problem might be? Thanks.

 

[joshjwc9]

Mach 460 stereos have multiple amplifiers, but I believe you have missed the final amplifier, the one that drivers the high frequency speakers like the tweeters. Their is a front amplifier underneath the stock cd player in the dash. If there was recent work or wiring done back their, it is very easy to pinch or cut a wire as it is so tight if one were to be installing a aftermarket deck. I believe mine cuts out from time to time at the driver tweeter. And for me, I replaced the speakers before testing the connection. Wires can corrode and break apart over time. Good Luck.

 

[brtnstrns]

Sorry, I should have been more clear. Its not the front tweeters, which I know are controlled by the front amp, which is why I didn't mention it. I know the subs are controlled by the rear amps. The tweeters work just fine, its the speakers actually in the door that don't work.

 

[BlackArtemis]

Those are not subs BTW, and it could be 1 of 3 things.

Amp has gone bad
a connection is loose
and both speakers are blown.

Most likely #1.

Try switching connections on the amps.

I am not sure if you can do this since i have long since ripped out the entire system and replaced it.

 

[patman0911]

Are the speakers in the rear deck working? If they are, the two amps in the rear are the same so you can switch them around and rule out or confirm the amp.

If it's all four woofers that are out then you'll need to start looking at the wiring as it's unlikely for both amps and/or all 4 speakers to die simultaneously. I'm not sure if the rear amps are on a separate fuse.
A quick way to test a speaker is to put a 9v battery across the terminals momentarily and the cone should move either in or out. If it doesn't move then you know for sure the voice coil is fried. If it does move, it's probably ok.

 

[brtnstrns]

I'll test the amp connections because it is only the door speakers that are out. Everything in the rear deck works fine. What are the door speakers then? Are they just mid range?

 

[wmburns]

Just to confirm the set up. Assuming this is a stock set up and no modifications done to the sound system.

What is the status of fuse F2.27 (25amp) in the Central Junction Box (CJB)? If my wiring diagrams are correct, this fuse powers all of the amps (but not the radio). Based on your reported symptoms, the fuse is most likely good but it never hurts to be sure.

My wiring diagrams indicate that the door speakers are driven from the left rear subwoofer amp. Since both door speakers do not work, the Left rear amp is a great common failure point.

Start by testing for +12 volts at VT/LB wire. The VT/LB wire is spliced at multiple points and present on connector C408 on pins 5,6,and 7.

The wiring diagrams indicates the left front speaker on wires ping 4(BK/LG) and pin 3(BK/WH). Measure the resistance. Should be 2-4 ohms. This will test the wires through the speaker coil. Or use Patman's test with a 9 volt battery.

If the speakers are good, this leaves the amp to be the failure point.

 

[BlackArtemis]

I'll test the amp connections because it is only the door speakers that are out. Everything in the rear deck works fine. What are the door speakers then? Are they just mid range?

Yeah, there is no sub in the mach 460 setup.

The fuse idea is great, if it only controls one of the amps.