red97vette

(a little long, but please read )

heres the story,
1997 vette, driven it over 20,000 miles with no major issues (have only changed water pump, and last week I changed the battery). Yesterday me and a friend installed a subwoofer and an amp, and we hooked it up with a line level converter (not the "PAC" one, just one I found at Best Buy).
We hooked up the amp power cable to the fuse box, and wired the line level to the pass rear speaker, grounded the amp to the pass seat bolt, also wired the remote wire to the "HVAC" fuse on the box underneath passenger feet (triggers amp to turn on when car is on). Worked fine, sounded marvelous. Drove the car today, everything normal. Leaving my gfs house at 1am tonight something interesting happened

I noticed the headlights grew dim for a fraction of a second (at the time i dismissed it and thought it was nothing), then about 15 - 30 seconds later as im driving, (i think) i hear a "poof" sound come from the amp in the back (the one hooked up to the sub) and my Airbag warning light (red light on the dash) came on, and i think maybe a few other lights came on, along with some "plinging" sounds (the kind when you forget to turn off your lights when parked).
I immeadiatly pulled over and turned the car off.
I waited a minute, and tried to start. Nothing. just "click". I tried again, and this time NOTHING happened, no lights...nothing, it was as if there was no battery in the car! ...very frightening...

I popped the hood, (thinking that this was stereo related, or caused by, i removed the (sill okay) fuse from the power line.

It was then I noticed a "hissing" sound comming from the radiator/MAF area. At first i thought it was the radiator cap that wasnt all the way on, and that the radiator was hot (this is what it sounded like).

After I tried pressing the brake pedal to see if any brake lights would come on...nothing...but the hissing sound went temporarly away...wierd.

A few min later help came, and we disconnected the battery. The "hissing" went away. We then waited a sec, and hooked it back up, hissing noise still not there.
I tired to start the car, still totally dead.
I got out of the car, and all of a sudden the interrior lights came on!

The car cranked and ran fine just as if nothing had ever happened.



Here is my question... WHAT happened? Has this happened to anyone before? Can I be 100% sure this is because of my stereo?

Im going to go out and check to see if i have gotten any "codes" but i have never done this before. Is there anything I should be cautious before going out and checking?

Thanks for reading! (Please help.. )

red

GrayC5

Although the subwoofer installation is cause for suspicion, it could also be any of several different things; i.e., bad ground, battery going bad etc. Below is a link that tells you how to run the diagnostics with codes specific to each of the model years through 2003. Follow the instructions there and you shouldn't have any problems running the codes.

Computer Codes for 1981 – 2003 Corvettes

Post any codes you find and someone here may be able to offer you some recommendations/advice. Good luck with the fix.

Stock Man

I am not sure if this is related but I had trouble with my Bonneville. Power issues. It turned out to be a breaker in the fuse block that would blow and reset after it cooled down. You may have just experienced the same thing. To much power being supplied by one circuit. Try splitting up the load or putting in a separate circuit for the stereos. My .02

red97vette

Isnt it wierd that ive gone 20,000 miles with no electrical issues at all, and then the 2nd day after a stereo install, this happens... *sigh*

tomarrow morning im going out to get the codes (too dark and cold right now...at 2:52am lol) Thanks for the website
Ill post them when i get em.
Has this every happened to anyone else here?


red

red97vette

Is this hard to do you think?

Ive read countless posts about how people have done the same type stereo/sub install and having it work totally fine... why does my circuit have to overload... (assuming thats the issue..its only a 398 watt RMS rated amp, and a 400 watt RMS sub)....


red

FiberglassFan

Car audio amps use what is known as a 'switching' power supply, which draws current in 'pulses' at the frequency the 'switcher' oscilator is tuned to, usually above 100KHz. By grounding to a seat belt bolt, all the current the amp is drawing must find its way through the frame and eventually back to the battery. The resistance of the frame will cause eddy currents to flow, and generate voltage noise spikes at each leading and trailing edge of the current waveform. This noise is in close proximity to the computer that runs the car, and can easily intermodulate with the digital signals in and out of the computer and perhaps event into the power supply of the computer too, though less likely. If you run a very heavy ground wire all the way directly from the amp to the (-) of the battery, and avoid any connection through the chassis, it is likely you will not suffer this problem again. Another thing I would strongly suggest is the instalation of a large filter capacitor across the + and (-) power leads close to the amp itself. I am an analog electronics engineer and been doing it for almost 30 years, trust me on this.....Most EEs being trained today don't know much about real world problems with system interactions. Car audio installers are even worse, most having no electronics training and only a minimal grasp of acoustics. I have had several friends with problem car audio installs and when they eliminated running the 'ground' through a chassis, all the troubles vanished. Its best to just use heavy wire both 'to' and 'from' a large load, and to NEVER use the chassis to carry current. Car frames and bolts are lousy 'wire', but this fact has eluded almost all the so called install experts. Hope this helps.

I make my living fixing exotic electronic problems as a consulting engineer, and also as a designer/custom builder of ultra expensive analog audio electronics. In addition we also manufacture very high performance interconnecting cables and A-C power conditioning products. check us out at www.jenalabs.com Jennifer

jcharity

I have a sub-woofer amp that I installed in my vet. Never attach your amp power cord to your fuse box you are looking for trouble. My amp power lead is attached to my positive battery post. Your noises could be a result of your battery discharging.

red97vette

thank you so much for that write up fiberglassfan! That was very kind of you to take the time for that lenghty writeup and help me out
I will try to run a ground to the battery from the amp.

"Another thing I would strongly suggest is the instalation of a large filter capacitor across the + and (-) power leads close to the amp itself." - do you mean adding a capacitator, like the kinda they use in uber powerful stereo systems?

This morning i went out and checked the codes on the car. Here is what I found: (and attempted to decode)

10 - PCM P1571H = "ASR Desired Torque"
2F - TCS C1255H = "EBTCM Internal malfunction"
AO - LDCM V1064H = cant find...
A1 - RDCM B2263H = "Horizontal Position Sensor Fit DCM-R"
A1 - RDCM B2265H = "Horizontal Position Sensor Fault DCM-R"
A1 - RDCM U1064H = "Lose of Communications with DCM"
BO - RFA C2120H = "TPM System malfunction (No Sensors Received -TPM"
38 - RTD NO COMM.


what does all this mean?

(btw, i removed the tire pressure sensors due to incompatable rims)


red

red97vette

anyone?



red

400hp

The "H" at the end of the code means "history" and also means that the problem was fixed and is no longer an issue.

69

Sounds like this car may have been a victim of the dreaded battery leaking issue. From reading your post, are you the original owner of the car since day 1?

OK so lets see if you were victimized….

When the battery leaks, the acid actually wicks into the POS/NEG cable, and like my car, I made the dealer change both POS/NEG cables because you could see the acid in the cables. Since your car is a 97, it may be possible that you have a cable that has corroded internally. Since you replaced the battery recently, (removing and reinstalling the cables) you may have actually accelerated this failure.

Here is what you can do, remove the battery and cables, go to Auto Zone, and have the battery and cables load tested (install the cables on the battery, and connect the load tester to the cables, perform the test).

Just a thought…
Kevin

Rob'sC5

Those codes looked to be the result of a current spike. I'd clear the codes and heed FiberglassFans advice.

FiberglassFan

'69' has some good advice on the high current battery leads. If acid got into them, thats a no-good situation! I wouldn't bother to test them, cause they will get worse and worse as the acid keeps corroding, and ther is no really good way to clean inside the wire to neutralize the acid. Just pick up a new set. Your codes DO look like current spikes, and resolved.....So the good news is that you probably have only a little work to do and not likely that any deep damage was done to the computer system.

Happy New Year!!!!!!!!!!!
Jennifer