Subwoofer

[bonmictx]

Hey guys - I've got the same situation with my 1994 850 Turbo. When he couldn't find easy access through the firewall, my shade tree mechanic friend mumbled something about using my cigarette lighter to hook up the wire coming from the amp in the trunk, and this really didn't seem like a good idea to me, but now I have validation! When my brother previously installed this amp & sub on my 240, he made a special point of buying the big-ass red wire and fuse and connecting it directly to the battery, and I figured there had to be a good reason. Incidentally, a few years back, this same mechanic friend lost a 240 to a fire that started in the tail lights. What really sucked was that all the green Volvo manuals and wiring diagrams that I'd bought for my '89 240 were in it. (Maybe I won't pay him in beer anymore.)

Thanks!

Michelle

[Matty Moo]

There's only one way to do automotive wiring, and that's the right way. Not a lot of room for mistakes when it's your car. It's one of those things you can't take shortcuts on or rig up.

I fried the wiring harness on my first car because I didn't know what I was doing. Luckily that was almost 20 years ago and the car was a pile anyway.

Never pass a wire through an opening that is bare metal. It will rub the insulation off of the wire.

[BEJinFbk]

+1 with a bullet!
And never, ever, ever connect that big red wire to the battery without a fuse within a few inches!

"But there's a fuse on the amp..."
And there should be, but it won't keep your car from
burning up if the Big Red one shorts to ground.
Protect the wire running to the amp.

[bonmictx]

What about powering the amp using the supply to the power antenna, which I had my friend disconnect because it was hanging up all the time? I think it has a 25 amp fuse...

Michelle

[BEJinFbk]

What about powering the amp using the supply to the power antenna, which I had my friend disconnect because it was hanging up all the time? I think it has a 25 amp fuse...

Michelle

A subwoofer amp uses a lot more juice than Volvo planned on
sending to the power antenna. That wire is way too small.

You really need a properly sized cable to the amp all the way from the battery.
Don't forget the fuse!

[bonmictx]

Can you tell me the drawbacks to having too small a wire? Is it likely to keep blowing the fuse? Is there fire danger? My friend says there isn't, because it's powered through the fuse box. I need help arguing my point.

Thanks so much!
Michelle

[BEJinFbk]

I don't mean to sound harsh, but, this is car audio 101...
If your friend doesn't know why this is a bad plan,
that friend probably shouldn't be working on your car.

Amp won't maintain voltage, it may shut down.
Low voltage has occaisionally killed an amp.
Using a small wire to run a sub amp of any decent size is
kinda like trying to fill a swimming pool with a garden hose.

And you may want to double check what size fuse is supposed to be in that location.
25 sounds pretty big for a power antenna. Someone may have
put in a bigger one as a low budget "fix". That kinda thing can
cause melted electrical systems and other nasty problems.

Best of Luck!

[bonmictx]

I don't mean to sound harsh, but, this is car audio 101...
If your friend doesn't know why this is a bad plan,
that friend probably shouldn't be working on your car.

Believe it or not, he's an ASE certified mechanic. Unfortunately, when working on his own vehicles (or mine), he'll try to MacGyver stuff and cut corners. I've learned to watch over him, and he'll do it my way when I insist. Since I'm not a mechanic, I just like to have backup when I do.

From all that I've read on the amp wiring, including your advice, I've decided the reason he's gonna do it MY way is because the amp just won't perform like it should his way.

(FYI -I confirmed that the power antenna fuse is 30 amp, and that's what's listed in my owners manual.)

Thanks for your help!

Michelle