No bass with factory JBL system (diff HU)

[RJGill84]

Hey guys, I'm new to the forum...and LOVE it so far! I have a 1994 Limited that is in outstanding condition...virtually ZERO rust (rare), beautiful interior, and no engine/transmission problems whatsoever. The only problem seems to be electrically related, and as I'm not the first owner of the vehicle I'm not sure what has been modified or not.

The main problem I am having lies with the audio system. It has the stock Ford JBL audio system with one amp powering the door speakers and one powering the factory 6.5" JBL subwoofer. I purchased the car with a Kenwood aftermarket head unit, and it worked perfectly fine for MONTHS. About a week ago all of a sudden there is zero bass, not only in the subwoofer, but in the door speakers as well. I tried the head unit in another vehicle, and it works fine. Keep in mind EVERYTHING was working, and nothing was changed at ALL.

This doesn't make a whole lot of sense to me because the sound is coming through the speakers just fine, except for the TOTAL lack of bass. I could see if maybe the subwoofer was blown or something then it wouldn't work, but what in the world would cause ALL bass from ALL speakers to be non-existant? Obviously the door speakers should have SOME bass, regardless of whats going on w/ sub & amp, and they don't. The sound is a little tinny and echoey as well. Occasionally the bass will come back on for a few seconds...booming and sounding TERRIBLE and then cut out again. I'm not an audio/electrical guy, so I'm clueless here. ANY help would be super appreciated! THANKS!

 

[Anime]

My guess is the Kenwood unit was wired in to use the factory amps, and just the sub and/or sub amp went out, leaving the speaker amp with a high-pass filter as the only sound, hence no bass. You'll need to pull the whole rear panel to get at the sub and amps if you want to check or replace it. If it does turn out to be the sub amp, and you want to keep the repairs on the cheap, I'd suggest getting a replacement amp on ebay. If it's just the sub, you can get a few cheap 6.5" replacements or a JL 6W0 for $90.

Definitely check all the wiring and connections first though, you sure don't want to go replacing parts if there was just a loose connection to the sub or amp.