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I just went and searched and read about 20 threads on similar cases, but none of them hit on what mine did. Tonight, I headed over to my Mother's for Christmas Eve. Got in the 89 305 TBI Firebird, let it warm up for 10 minutes like I always do. It seemed normal as usual driving, but about 5 miles down the road at the first stop sign, I started smelling a REALLY strong burning electrical smell. At first, I thought it was something in the air since there was no smoke coming from the interior or under the hood, so I drove on about 55mph for 4 more miles down a highway. I get to a stop light and there it is again. At this point, I'm reaching behind my seat and putting the fire extinguisher in the passanger seat to get ready to bail and put out a fire. Traffic is heavy and I'm only 2 blocks from a gas station at this point, so I get it there and leave it running, except now the smell is gone. I search all over the engine bay, nothing. I pulled the fuse door, nothing. No smell. I've got my nose all over the engine bay, and all over under the dash and nothing, no sign.
I got back in the car and didn't smell it again for a few miles in stop and go traffic. I'm also heavily watching my gauges, staring at the hood, and really smelling deeply as I drive. The headlights are on and all my dash lights are working fine. During the smells, the car isn't acting weird, nothing is failing and it seems fine. Once I get to my Mother's, there it is again stronger. Again, no smoke, nothing burning on the manifolds, just this smell. I got back home 4 hours later...(just a few minutes ago) and it didn't do it anymore at all...not even a trace of the smell all the way home. You can bet I had the fire extinguisher by my side the whole time though. At any rate, I've unhooked the battery and it's sitting in the driveway safe. I'm a little concerned that it came and went like that, yet nothing is wrong with the car as far as I can tell. Nothing failed or tried to fail and there was no change in drivability or anything.
Whatever it was, it's gone, but that can't be good. Something either got hot, tried to fry, corrected itself, or is about to come back with a vengence I fear. I did see a link about possible main wire harness rubbing the top of the frame of the fuse box metal. I'm going to check that first thing, but other than that, I have no idea how it could come on so strong, not affect the car in any way and then vanish.
Well, before the start of Christmas time with family, I took off all lower dash panels and kick panels early this morning and studied every wiring harness and wire in my dash that I could see. I also took out the radio and a/c-heat control and studied all of that wiring. Aside from a crappy aftermarket cd wiring job (which I fixed), I found no trace of burnt or melted wires anywhere. The "installer" of the cd player decided twisting together wires with electrical tape on them was good enough, however there were no signs of problem, but I fixed it all anyway because I hate when that's done like that. It's too bad my factory radio wiring harness plug was cut and is gone, but at least I now know this.
I pulled down the fuse box frame and sure enough, there was a slight indentation in the engine harness tape from the sharp metal, but it was NOT through the tape yet. I checked it anyway and all wires were safe. I went ahead and natuarally fixed that little problem so that it will NEVER cut through, but I could see how it might have a few years down the road had I not inspected it. Also, I went through the engine bay more thoroughly and no sign of melting or problems. Nothing around the starter or underneath either.
I loaded it up with presents, drove to my Father's place and smelled it again once at a stop sign after driving for 15 minutes, but then it never came back the rest of the way there or on the way back home. It's got me puzzled. It's definitely the smell of burning wires/electrical components. I've burned out some amps and wires in cars before and it smells just like that. Yet, there is no trace of a problem so far. The only car audio in the car is a Pioneer CD player and two 6x9s. There's no other audio at all, not even front speakers which I discovered when I replaced the dash pad. I checked the 6x9s as well and no sign of problems there either. I'm clueless right now. I've got my fire extinguisher on stand-by and keeping a keen eye on things, but not sure what is happening or what will happen.
I remember 15 or so years ago going to junk yards and seeing Firebirds burned to the ground all the time...so I'm a little worried.
My next phase after this snow storm passes is to remove the center console shift plate and study under there, then I'm going into the steering column to check in there (gotta tighten the column, so what a perfect time for that).
Other than that, I have no other ideas of where to look or what is causing this. I suspected the alternator, but the voltage is normal both idling and driving, so I'm at a loss here.
could check if the fuses are heating up-seems they can develop a bad connection where they plug into the brass contacts of the fuse panel after they sit undisturbed a couple decades-noticed that happening with several fuses on mine about 5 yrs ago-just pulled them out and reinstalled to fix the problem,so far they haven't heated up again.Presuming you are running the heater blower in these cold months,could be something on the blower resistor "cooking off".
Our cars have a plug under the dash that all of the 12V passes through for the Heat/ac system , and this plug overheating and melting is a common problem . The guy "SofaKingdom" was mentioning this plug the other day to someone else in a different thread , and it's something you will want to check for . It's behind the heater control head if I recall , and usually looks really melted by the time it's found .
Try running it without the heater on , see if the stink is there . If not , turn on the heater and see if you get the stink . If so , it's far more likely to be the plug rather than anything cooking off of the resistor , since the resisior usually wouldn't produce a plastic/electrical smell like a melting plug connector will .....
Definitely not the resistor or any other area associated with the heat/ac in the engine bay. I checked it all. As for that possible melting plug...that could be it. When I had the a/c heat control out, I saw the wires, but I did not notice a plug farther up in the dash. Guess I'll be pulling that again and looking a little further. The heater is on all the time. I haven't tried or thought of driving it without the heater on to see if the smell is still there because it's just too cold.haha
So, if I understand this correctly, this is a single connector plug for the brown 12v wire going into the a/c heat control unit? I can get to this fairly easily without taking the dash out? I don't recall seeing it before when I was in there the other day.
Thanks for the info!
Originally Posted by init4fun
Our cars have a plug under the dash that all of the 12V passes through for the Heat/ac system , and this plug overheating and melting is a common problem . The guy "SofaKingdom" was mentioning this plug the other day to someone else in a different thread , and it's something you will want to check for . It's behind the heater control head if I recall , and usually looks really melted by the time it's found .
Try running it without the heater on , see if the stink is there . If not , turn on the heater and see if you get the stink . If so , it's far more likely to be the plug rather than anything cooking off of the resistor , since the resisior usually wouldn't produce a plastic/electrical smell like a melting plug connector will .....
Ok, so I'm having trouble locating this suspect connector. I see the brown power wire at the back of the hvac unit and it has a connector about 2 inches away from the unit. This single gray colored connector connects the brown wire, but it's real close to the unit. I studied it and it looks brand new inside and out. I couldn't find a connector farther up in the dash as stated. Where abouts specifically is the suspect melting connector? Is it taped up in the harness running under the steering column or is it out by itself somewhere? I didn't see an additional connector in there and I had the hvac/radio out, drive's side hush panel, trim panel removed. I could see all up in there, but maybe I'm blind or not looking in the right place.
At any rate, it hasn't done the smell thing anymore so far driving it a couple times, but I'm still concerned.
Last edited by kentuckyKITT; 12-31-2012 at 09:50 PM.
Reason: spelling
Not trying to necro bump this thread but I couldnt find much on this either. I just picked up a trans am yesterday and I put in my battery for the first time... I started playing with all the buttons inside to see what works and what doesnt and when I got to my headlights I wanted to see if my headlight motors still worked. One popped up and the other didnt, so I gave it some assistance and it came up fine, then I tried to see if the head lights would go up and down on their own around 3-4 times and then I started to see a faint white smoke come out from behind the headlight button. What could that be?
and KentuckyKITT did you figure out what your problem was after all this time?
Not trying to necro bump this thread but I couldnt find much on this either. I just picked up a trans am yesterday and I put in my battery for the first time... I started playing with all the buttons inside to see what works and what doesnt and when I got to my headlights I wanted to see if my headlight motors still worked. One popped up and the other didnt, so I gave it some assistance and it came up fine, then I tried to see if the head lights would go up and down on their own around 3-4 times and then I started to see a faint white smoke come out from behind the headlight button. What could that be?
and KentuckyKITT did you figure out what your problem was after all this time?
The head light switch I would suspect. These are old cars and if it sits the connectors get corrosion on them. Also there is a paste inside of the switch. I would pull it out and clean it. There is also a link inside of the switch so if it has a hardcore load put on it it will fry. You could have been flipping the switch too fast and put a load on it, and smoked a bit of the paste.
The link is the silver part in this photo.
No, I never did find out what it was and it has not done it since. I still have the car and I drive it daily when the weather is nice. Whatever it was, it's gone and I may never know what it was. It's been 4 years now, so whatever it was corrected itself. If you have smoke coming from your headlight switch, you should get that out and check things, at the very least replace the switch. These switches do go bad and usually in my experience having owned 7 thirdgen Pontiacs, when the switch goes bad, it will not close the headlights unless you hold it or have to press firmly. When it starts to do this, I usually replace it. I've never had one smoke though.
insane! You hit the nail on the head! I'll have to take this out and inspect it. I was afraid to touch other buttons and radio thinking my fuses were bad or things were grounding out or something haha. Yes you're right, I was pressing the on and off switch every 5 seconds or so to test the head lights. After I saw smoke I turned off the car and prayed I didn't ignite it haha.
The head light switch I would suspect. These are old cars and if it sits the connectors get corrosion on them. Also there is a paste inside of the switch. I would pull it out and clean it. There is also a link inside of the switch so if it has a hardcore load put on it it will fry. You could have been flipping the switch too fast and put a load on it, and smoked a bit of the paste.
So you think I should clean all of that paste off completely? or buy a used/junk yard one? Do these come in a new reproduction model?
Forget the junk yard one. I picked up a brand bew one from vatozone for 15bucks. Only to find out I don't need it. You can clean the paste off and put some computer chip paste back in. I guarantee It was that link inside the switch. It was good enough of a load put on that switch and it got hot but not enough to pop it.
12-24-2012, 09:53 PM
