Corolla Stereo Issue

This is sort of unusual.

I would check the wiring first. Did you cut the harness, or did you buy a connector adapter and wire it that way?

Either way, I would make sure the wiring is proper, and that you didn't reverse anything, and that you didn't inadvertantly ground anything.

Also, you didn't use a Common Ground for all the speakers, did you? On these higher powered units especially, it is important that each speaker has it's own ground.

You don't mention any amps. Did the car have an amp of it's own? It may still be running open-loop, which isn't good, but also shouldn't be causing your Alternator light to come on. I suspect more a wiring issue. Or:

Try this: leave the stereo off, and run some other accessory, such as the air conditioner on full blast, or the rear window defroster. This will also put a load on the system and will then tell you if the fault is with your stereo or the electrical system.

Good luck; let us know what you find!

Hi,

All I did when wiring it in was simply cut the wires, splice and solder the new harness in and seat the unit. No polarities were reversed or anything. Similar story for the 6x9s, cut out the old parcel shelf speakers (stock) and cut holes in the shelf to fit them, just cut and spliced the cables again. Same for 4 inchers. I should also note that the battery is pretty much brand new, and that there is no amp in the car at all.

Cheers.

When you cut and spliced the wires, you probably figured out that there are

2 power sources for the radio, one that is always hot and one that is switched with the ignition. Assuming that you used the factory wiring and did not change fuse sizes, there should not be a short in the system, although it would not hurt to check to make sure that the splices are well-insulated. Hopefully, you used shrink tubing and not just tape for insulation.

If all the wiring is OK, then you should check alternator output. A service facility can check output for you. It is possible that the alternator's output is marginal.

First, check the battery connections (both ends of both cables). And the alternator connections as well. And check the voltage across the battery with the engine running, I think it ought to be rising to about 14 V but not more than 15 V when revving to 2000 rev/min.

A "high power amp" wants a lot of current even at low output, so do not play for hours without the engine running if you want to start up and drive home afterwards;).

I think Hachiroku means it right, but I would rather say that in a "high power amp" system none of the loudspeaker cables shall be grounded or connected together. That means that each loudspeaker shall have its own pair of cables from the amp. That may not be so in all original wirings, but at least in my diagram for a

88 European Corolla it is.

Asbjørn

Thanks so much for your help. Correct, I used the factory wiring as it was. No changes made. Battery sits at 12.3V with no ignition and rises to 14.4V with ignition on at idle. When I pump the stereo at idle it drops to 14.3V. I'm not convinced that's significant. A mate with a bit more experience recommended I buy an aftermarket amplifier to run the

6x9s, as he said they'll drain a lot of charge when hooked up to the head unit. No fuses are blown, and everything is grounded correctly. Is buying a 'real' amp the way to go? Again thanks for your help. Glad there's people out there who know their stuff!

They really shouldn't put much of a drain on the system. 4 or 8 ohms is 4 or

8 ohms! It's the amp (either the built-in amp or a separate amp) that's going to draw the current!

It's too bad you cut the harness. They make adapters that just clip in and would be a hell of a lot easier to troubleshoot than just bare wires.

I'm still betting there is a wiring error somewhere. I'm sure you probably have, but just check the +12V Constant and the +12V Switched one more time, and also check your grounds. If it's not grounded properly, some other ckt will try to ground through it and put an extra load on the system.

What I do is I use the ground from the original harness, and then also run a ground to the chassis somewhere, usually to the frame provided to install the radio. If this is plastic in your car, then find another good earth to connect to.

BTW, did you try leaving the radio off and turning something else on? This is a quick, off-the-cuff way to check the alternator/charging system. Also, you could tap a voltmeter somewhere and monitor it while you turn different things on and off.

The best thing, of course, is to bring it to a garage and have the alternator tested.

Howdy again.

Just to clarify I didn't cut the harness, i just spliced the wires back after the fuse box (on the head unit power wires) and then rewired it to the factory cables from the battery/to the speakers (using heatshrink). So the Sony harness is being used.

I doubly checked the 12V cables again today, with no problems. Everything is as it was when I removed the stock head unit. No wires crossed. Also, the charge still only drops battery to 14.3V even when I run the head unit flat out, the lights on high and the doors open (internal lights on). It's interesting to note that the interior light dims to the bass, while there are no visible effects on headlights or dash lights.

Thanks.

Wow. I wonder what you tapped into.

I would go to the local Stereo Store, or (at least here in the US we can get them at Wal*Mart) a good department store that has an audio section, and look for the adapter harness that adapts the wires from the Sony harness to the OE Toyota harness. Here they are $7 USD.

The only problem I have had with an XPlod was when the bass hits the lights on the unit itself dims.

I did have one car (Corolla GTS Trueno) where the headlights dimmed, but this was in the Dark Ages before Hold Up Caps, 4 amps and 1200 watts!

Hey,

I have no idea what's going on here. I had an auto electrician look at it today and he said the wiring was 'top notch' (Australian for bloody good :P). So I'm a little stumped. However, he also suggested buying an amp, and maybe also a capacitor for it. Thing is, I only want to drive a couple of 6x9s, not a whole setup!

So anyway I've been looking at a few amps, but I dunno. Speakers and head units, fine... Amps are a whole new world to me. What do I look for? Do I just need enough power to run the speakers (ie. 2 x 50W RMS) or do i go higher? Tell you what if I have to buy one of these things and that charge light dare shows its head again I'll rip it out and eat it.

Hmmmm...should I tell him what I have in my Supra and my Corolla GT-S?

Haha OK so you gonna tell or what? :P

Now don't laugh, but it's a lot of 'Optimus' stuff, the 'better' end of the Radio Shack stuff. I got most of it when RS was getting out of the car stereo biz for pennies on the dollar...

The Supra has a 400W amp under the seat, 100 per channel. There is also a bridged amp in the trunk, 250x2 (500 total) for the 12" sub.

6.5" REAL (German) MB Quarts in the doors, and 5" MB Quarts replacing the factory 4" speakers in the rear. NOT an easy installation; you have to pull the whole interior of the car out except the seats and dashboard!

I don't go for thump, but I am a bass player, and the Supra is the 'Sport Roof' (Targa) so it needed some sound. All driven by a JVC Arsenal MP3/WMV player, XM Satellite and an Alpine EQ built in to the double-din dash opening. Speakers, EQ and Arsenal from E-Bay for a total of about $150, and the amps cost $19.95 for the 250 watt amp and $36 for the 400 Watt model.

The Corolla has an Alpine Cassette player (it's an old car!) custom mounted in smoked Lexan (HINT: If you're going to cut Lexan, pour cold water on it!!! it took me 3 tries!!) an old Sherwood EQ I bought from the demo rack for $10 about 10 years ago that fits where the optional OEM EQ would have gone, a Fujitsu-Ten 40 Watt per channel running 4 1" Audax dome tweeters, an Alpine 100 watt amp running the 8" rear mid-woofers from an old pair of home speakers in a custom box, a Panasonic 65 watt amp running the front 5.25" JBL's mounted in the dash, and a 150 watt Jensen running 2

10" woofers in the rear deck. The Jensen and the Fujitsu-Ten are on home-made band-pass filters (actually, tunable EQ's made with OP Amps) that send the lows to the woofers and the highs to the tweeters, and everything is controlled by the Sherwood in the dash. All amps are Per Channel ratings. The Corolla doesn't need as much raw power because it's a quieter car, and all the amps are very clean amps, so the sound is good even at low levels. Again, I don't go for raw THUMP! but both these systems sound as good as good home set ups.

Total for this car was about $500 between 1991 and 1996, but pieces have been cannibalized for other 'projects'.

This was all done on a budget; with two kids it was tough scraping up the right pieces, but I waited and bought decent stuff when it was being discontinued, etc. so I usually spent pennies on the dollar. I like the way the systems sound; I'm almost 50 so Rap and Hip Hop are out, but for stuff like 3 Doors Down, Wheezer and Audioslave it is more than adequate, and for softer stuff like Cranberries, Coldplay, Green Day and Oasis it is superb. It even handles Godsmack quite well. The only thing I would change would be the sub and maybe the sub amp. The amp has enough power all in all, but the speaker is mounted in an old Pignose amp and really needs upgrading. I have an older JBL sub in a nice enclosure, but it's TOO bassy! It shakes the freakin' car! Here's a pic of the Pignose; we ported it and closed up the back so it can handle the bass.

I like the way it sounds. If you're into trance, Rap or Hip Hop there isn't enough thump, but there is enough bass for a bassy bass player like me!

Okay, how does it do on Don Dorsey? Beethoven Or Bust, Bachbusters.

When you tell the synth to make the equivalent of a 200-foot pipe organ rank driven by a 1000 HP blower, it can do it. (0 Db digital at around 8 Hz. When it thumps, it THUMPS.)

And woe to the person who cranks up "Toccata and Fugue in D minor" and only /thought/ their amps and subs were up to the task... ;-)

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Haha Bruce that's rough :P. Shit Hachi you have some serious 'amplifiage' in those cars :P and I thought having one amp was a problem lol :P

All with no caps, not distribution boxes, etc.

Now, on my next build, I might get SERIOUS! (The kids are on their own...)

I sure can't complain about the MB Quart speakers, though! One set cost $30 off E-Bay, and the other cost $46. They are rated at 100 watts, and are such a pain to get in and out of the Supra they will probably just stay there. The Optimus amp sounds ok, so I might just swap out the sub and the amp running it for something with a little more OOOMPH!

If the Corolla ever gets rebuilt, it's going to have some roof-popping sound!

You guys really don't know what you're doing to your future do you?...poor little unclued suckers, you're all headed for a retirement of hugely deficient hearing ability...it ain't fun son. Just like my grandkids you all think you're immortal, I can only shake my head in pity...

What did you say, Gord?

Both my Navy and Air Force son's say even with protection, they fully expect to lose a portion of their hearing.

Exactly...but a helluva lot less loss than with NO protection which is what we had...mind you a rather benevolent military (Canadian) has tried to recompense us for their lack of knowledge of the dangers of noise pollution with a pretty generous disability pension scheme...