You state the original motor overheated when the insulation fell on the housing. Are you sure about this? I would think the motor would no longer operate if the internal mechanism became so hot to give off a strong smell. Are you sure the new motor is overheating? Does it feel very hot when you touch the housing? You stated you have changed the motor from a 1/3 HP to 1/2 HP. Have you set the air flow so that it is the same as the 1/3 HP motor? The smell may be coming from something unrelated to the motor. If the smell is giving you a headache then you should have a professional inspect the heat exchanger. You may have a more seious problem.

I guess its not as old as I thought. It has a solid state board and is marked on the decal 1993. its really filthy on the inside. should it be blown out with compressed air? the GMC model number is as best as I can read it GMP100-4 Rev 8 or B. The tech the home warranty sent out replaced a part that made the heater come on but said he couldn't do anything about the fan coming on. he wasn't that great he left the drain tube unhooked, the filter half-way in and cut connections inside the unit instead of throwing them away in the trash can right next to it. I guess Ill call the home warranty people on monday. he did get the heater going though. any thoughts? I also noticed it has 2 fans a small one above maybe to exhaust CO? It and maybe the big lower one comes on when the door in replace and stays on a few minutes. is this normal? if not it may be a way a tech could check it since he said it had to be on when its not supposed to be before he could fix it. I took some pics of the inside here is a link to the album. thanks!!!! Here is a link that might be useful: furnace pics

That may have sounded like a political attack Elmer, now that I reread it. But I meant that as a joke. I believe it's true that licensing and regulations increase costs. In Texas, to get a *true* HVAC license and not just some registration with the state as in a technician --- you need 4 years of verifiable experience, someone with a *Real HVAC License* to vouch for you for that 4 years of experience, then you have to take and pass the HVAC license exam with a 70 or better. It's a timed test, but open book. It's by no means an easy test. You also need to have the means to buy and maintain General Liability Insurance. Open book is easy: uh, no. The test covers multiple books, the refrigeration book alone is like a phone book of a major metropolitan area that is if you're old enough to know what a phone book is. I believe it's a dumb approach when you have to pull a permit for everything and anything. It's mostly a money grab in my opinion. Those permit rules are implemented by politicians. We have to pull permits here in the city limits. Most of my work is in the county, there is no requirement to pull a permit in the county here. (That makes the job easier to get done and move onto the next job, which is important in this climate. California climate is nothing when it comes to air conditioning, in most cases. ) With that said, I know what the building code is in Texas and I follow it, even though I am not pulling a permit 99% of the time. ------------- The point that was lost though is that your climate would make it extremely difficult for an HVAC technician / installer to make a good enough living only doing air conditioning work. This is why I was against moving to a more moderate climate. I wanted to work doing what I wanted my career in HVAC to be about. Mostly air conditioning related problems. I don't regret that choice. The only choice I regret is not getting my HVAC license sooner than what I did. But I probably wouldn't have as much knowledge as I do from the myriad of employers I worked for over the years... seeing different ways of doing things. This is why I said: HVAC installer is a dead end job. I believe it would be true even for California, because you'd never make enough to support yourself *only* doing AC installation work.

It is possible the filter is too restrictive, but likely not the problem if you have used the same filter in the past. Have you recently closed any of the supply vents? Are the dampers to the zones operating properly? When was the last time furnace has a preventative maintenance check? The furnace is shutting down due to a safety issue. You need to have this have a professional determine the cause and the fix. Since it is only 6 years old you may be covered by the parts warranty. Call the company who did the installation if you feel they are competent.