ppritchard

Drove maybe 5 minutes, smoke started coming out of the vents.
Then I saw a flame under the dash to the left of the glovebox. I have the glovebox out of the car, that's how I could see the flame.

Anyway, tried to put it out with a towel but couldn't, turned around and drove back home grabbed the fire extinguisher, pulled the pin and Nothing! Now the flame is burning the plastic, So I grab the water hose and spray it out.

What caused the fire? Pics show a finned metal something just to the left of the glovebox and it looks like the origin or something right there.

I pulled the radio, it wasn't from there-- wires are all fine there.

I've searched, but all the Fire posts are about under hood fires.

As always, thanks for any help.

ppritchard@cfl.rr.com

ppritchard

Is that "finned" piece the amp for the center speaker?
That's the only thing I can find a pic of that looks similar.

Could a center speaker amp catch fire?

thanks for any input.

ItalynStylion

iTrader: (1)

It's definitely a heat sink for something. Not sure if that's an amp (I kinda thought it was internal to the headunit) but it very well might be. Regardless, it looks like it's close to where the fire started. If you had only been driving 5 minutes I doubt it could have heated up quite that much though. It wouldn't have had time to get THAT hot.

My money is on some bad wiring or something electrical.

jsesq

Glad to hear that you and the car are (mostly) both ok! I'm thinking that I should look into getting a fire extinguisher to keep in the car.

Speed of light

iTrader: (8)

That is the center speaker amp. Does the car have a Bose system? Was the center speaker connected and working?

This is not the first report of the center amp catching fire. More info and some forensics would be helpful to identify a potential hazard/trend/failure mode.

Spalato

iTrader: (33)

Damn, glad you're ok!

ppritchard

Thanks,
Speed of light-- first time I've heard of an amp fire -- but the precursor was a whining noise from the speaker, just like an old distributor wiring problem. That was my only warning that "something" was amiss with the audio.

Are there posts on other fire issues? If so, I couldn't find them.

2. center speaker was working, but with the buzz/whine I mentioned.

thanks,
ppritchard

ppritchard

Video of "fire" area.

silverTRD

iTrader: (36)

Def an amp in my opinion. This same thing happened to me in my Toyota Tundra. My fd has the bose in it and I think It may be time to remove it. I didn't know it was a problem. Maybe I'll get a speaker pod, hmm

Keep us posted upon further inspection and repair. Thanks and good luck

ItalynStylion

iTrader: (1)

If the speaker was giving you hints that the source powering it was calling it quits then that sounds like your answer. Though to be honest, as an audio amplifier and speaker designer, I wouldn't have thought it could really heat up to beyond operating temp in less than 5 minutes. Certainly not unless you were just jamming like crazy.

Unless of course, the fire wasn't due to the heat sink getting to hot and it was really due to some capacitors blowing up or something. That DEFINITELY has the potential to cause a fire. I melted some caps on a 350watt plate amp in a home theater sub I built about 5 years ago. It toasted some of the poly fill inside the enclosure.

Glad you're ok though. Could have been a LOT worse!

SA3R

I'm glad you caught it in time. That could have become so much worse...!!

This speaker amp- is it only in Bose equipped models or is it in all models?

I have seen a small clarion branded amp metal looking square thing in the center of my dash, behind the stereo unit on my RHD car. Is this the same thing and should I remove it??

Fire freaks me out. I had one car burn to the ground from bad factory wiring and insurance didn't cover it.

Speed of light

iTrader: (8)

Clarion was, I believe, the vendor for the 'standard' system. They certainly made the head units. I don't know if they manufactured units for Bose, however. (After viewing the pic on a real computer, that def is the Bose version of the amp.)

So it sounds like the amp became unstable and went into oscillation; a condition which can lead to thermal runaway and catastrophic failure.

For those who would prefer to keep the system, it might be worthwhile to splice a small 4 or 5 amp fuse specifically in the B+ lead to the center channel amp, which might better protect the amp against such a high-profile failure (than the 20 or 30 amp 'main' system fuse apparently does). That's what I'll be doing.

If you search the board, I think you may find another member that reported the same failure and fire not that long ago. I hope this isn't trending.

ppritchard

I've searched and read all the fire threads, but I didn't see the other amp failure that you mentioned, anyone have the link?

Sgtblue

iTrader: (16)

https://www.rx7club.com/interior-ext...nterior-90394/

https://www.rx7club.com/interior-ext...oubles-611695/

https://www.rx7club.com/interior-ext...cement-294476/


Hate electronics and have no real understanding of what the OP is saying in this thread, other than how the amps might fail:
https://www.rx7club.com/interior-ext...-guide-885516/

ppritchard

Thanks for the links.

ItalynStylion

iTrader: (1)

This is very good advice. And honestly, probably don't even need quite that much amperage. I'm sure that little amp isn't even supposed to make more than 15 watts or so without clipping the hell out of the signal.

ppritchard

Ok -- pulled the Center Bose Amplifier. It appears that the top side either was hot enough to melt or hot enough to catch fire and melt. The only other burnt area is the adjacent plastic that runs along the left side of the glovebox. Since I do Not see other hotspots, I'm guessing that the amplifier was the source of the heat/fire. The wiring is on the bottom and did not display any damage.





The Only other electrical source nearby would be the glovebox light, but not likely.

Speed of light

iTrader: (8)

Here is the link to the other thread that came to mind:

https://www.rx7club.com/3rd-generati...aster-1040757/

Italyn: I agree with you about a smaller fuse size for a 15 watt (RMS) amp. Given the size of the heat sink, I assume that it is a class AB linear amp (probably chosen for low distortion and low noise).

So considering the 15 watt output and a 66% estimated efficiency, a 2 to 3amp fuse should suffice. This pretty significant since it reduces the available input power to the amp by at least a factor of 10x, which would probably be preclude a major meltdown such as that depicted; e.g., with a smaller fuse, the amp would be limited to say 35 watts total input power--as opposed to say the 350+ watts that melts everything and/or ignites.

ppritchard

Thanks for the link, appears to be the exact same event.

Exidous

I'm really glad I pulled that YEARS ago. That fire was definitely from the amp. Glad you and the car are mostly okay.

Sgtblue

iTrader: (16)

ppritchard

Closer examination reveals that the a/c duct from the center (above radio) to the right hand vents has melted away. The vent tube was plastic and ran just above where the amp fire happened.

Has anyone replaced that a/c duct run? If so, how did you do it?

Thanks for any help.

ppritchard@cfl.rr.com

JM1FD

iTrader: (1)

According to the shop manual, this amplifier was moved to the center console on the 1994 model. Guess that explains why my center console has been getting so warm. Time to send mine to the retirement home!

JM1FD

iTrader: (1)

Got my amp out. It was definitely overheating but hadn't yet caught fire. I can post pics of it with the cover off if anyone can possibly identify a root cause.

One of the screws holding the cover on was corroded, and it happened to be near the largest capacitor on the board so I'm wondering if it sprung a leak and ceased to capacitate? It wasn't bulged/distorted, however.

ppritchard

Glad you found it in time, no fun trying to reconstruct melted parts.