Tipically, a hot air furnce has exhaust and a cold air intake. My question is, why is one of them hooked to condensation pump that pumps water out?

<span>Here's the story on the P0410:<br /> <br /> The AIR pump adds air to the exhaust stream to lower emissions. It does this by taking in outside air and pumping it through two one-way check valves into each bank of the exhaust.<br /> <br /> About 90% of the time that this code is set, the one-way check valves have worn out or failed and allow water (which occurs naturally in the exhaust) back into the pump. In any cold climate, especially in the northeast with higher humidity, this water may be more excessive. The water partially fills the AIR pump, it can then freeze. When the PCM commands the pump on, if the pump is frozen it cannot turn, thus overloading the circuit and "popping" the fuse.<br /> <br /> As far as the location of the fuse, it is in the right front fender well beside the battery, and in front of the horn there. <br /> <br /> Sometimes replacing the fuse will fix all your problems and you are all set until next winter when it all happens again.<br /> <br /> Also, sometimes water is allowed to enter the pump through the intake side of the system (just a 5/8" hose behind the fan shroud) and ruins the system that way. -I'll talk about that in a moment.<br /> <br /> GM says that when this system failure occurs due to water intrusion, the pump MUST be replaced. I have had decent luck just blowing the pump out with direct power provided by a test bettery out of the vehicle, and saving the customer some $$$ :thumbsup: <br /> <br /> GM has also released a remote air intake kit that includes a longer 5/8" hose, a control solenoid, and a one-way check valve to eliminate most possibility of water intrusion.<br /> <br /> Like I said before, sometimes just blowing out the motor and replacing the fuse will solve your problem. BUT, to truly repair the problem correctly the AIR pump, the fuse, and the exhaust check valves must be replaced, and the remote air intake kit must be installed. :banghead: $$$<br /> <br /> I have much experience with this AIR system. Here in the northeast it is a BIG problem, and we have replaced at least 100 AIR pumps in the last 2 years or so. <br /> <br /> If your vehicle is still under warranty, then you are lucky. --&gt; The exhaust check valves usually wear out after 3-4 years thus, putting most vehicles out of warranty coverage. :sly: <br /> <br /> Hope this explains the infamous P0410.</span>