Monte Brethren,

Recently I've been having an electrical issue somewhere causing the headlights, dome light, dash lights all to flicker bright to dim while driving. I've tested the alternator output and it is strong at 14.5 and the battery tested fully charged. I think it may be an issue with the amp and sub in the trunk, however I'm not tech savvy with such things. I had them put in when I bought the car 9 years ago and they were used equipment when I purchased them. I was thinking a chafed wire somewhere? This started about three months ago and is seemingly getting progressively worse. Anyone have a clue if I'm on the right track before I start ripping sh*t out of this car. It's about to drive me insane......Thanks in advance...

 

Isolate the circuit feeding current to the amp and sub in the trunk — you should be able to do that by disconnecting the power lead.
Then, clean up all your grounds — that includes the surfaces where the alternator mounts to the engine, ends of the grounding straps from the engine to the frame, frame to the body, body to radiator support, engine to body, etc. and the surfaces on the frame and body panels where the straps mount/attach; I know how tedious that sounds but it doesn't require anything other than basic wrenches, screwdrivers, steel wool and some time. If a wire or a strap seems questionable, replace it, don't waste your time trying to salvage or reuse it. Adding additional grounding straps does not hurt in the least. You'd be surprised how many mysterious electrical issues go away when really good ground is achieved. By the way, electrical current will flow along the path of least resistance. If you have an automatic transmission, when you don't have really good ground, current will flow through the transmission and erode the bronze bushings inside your transmission causing premature failure.
In other words, don't take your grounding for granted.

 

Does the dimming correspond to when the sub hits?

Should be even easier than that - if it was installed properly, there should be a large fuse very close to where it hooks to the battery. Most fuses can be removed in seconds without any tools at all.

 

It does not correspond to when the sub hits. In fact, it wasn't doing it at all this morning on the drive in to work. I won't have time to tear into it until the weekend. There is an 8GA fuse link wire running to the battery. I will look there first. Fortunately, I work in the quality department for a huge wire and cable company, so I know a little about things like that. The destructive testing we put that stuff through is pretty cool...... That stuff can take a punch, but does have its failing point...

Thanks for the input, guys!

 

Well, one problem goes away and another rears its ugly head.... I had a fog lamp bulb blow so I replaced it. Immediately, the "flickering" issue went away completely. I don't get it, but why question it.... Everything still tests strong.

Friday, took it out on the highway and as soon as I got up to speed, the TPMS readings went out. All of them, prompting the warning light on the dash. They were all replaced about a year or so ago, so the likelihood of them all going bad at the same instant is about the same as hitting the powerball.... Has anyone ever replaced a control module for this? I didn't see a fuse marked for this particular purpose (although it's possible my rage was affecting my vision...). I was hoping that it was that simple. I'm thinking I may have to go the dreaded dealership route on this one. I'm gonna need this car for a road trip in 11 days and I was already going to treat it to a new set of tires....

Old cars.. If it ain't one thing, it's another...... Already looking for this one's replacement.