Pontiac Repair: a few things, maybe related??, pontiac montana, corrosion problem

Question
Hi I have a 2000 Pontiac Montana van and I have no heat at any setting at anytime while the vehicle is in operation? Before it stopped working there was a loud squeal coming from the glove box/vents, I thought it might be the blower motor? However just recently I am having problems with the electrical system: I put in a new battery, 1.5 months old, and have an alternator putting out over 14Amps, but lately when I WAS driving it periodically the check engine light would be on, been on since I bought the vehicle, and every so often I would shut off the engine and ALL POWER would be lost! No lights, radio, auto door locks NOTHING! Put tester on battery and battery is fully charged, this is where the funny thing happens, I found that if I open the hood and pull the fuse relay to an angle between 45 and 90 degrees I prop it up and jump in and the vehicle starts without any problem! The check engine light goes out, and then it works fine for a bit, but then if I leave it over night in my driveway and get in it in the morning it might start, but the check engine light comes back on and the next time I shut it off NO POWER AGAIN! WTF is wrong with this POS! Thanks Jason

Answer
Hi Jason:

well sounds like you have a bunch of issues here. I would check the blower motor for power and ground at the motor with a 12 Volt test light put the motor on hi speed turn the key on the across the 2 wires you should have a BRIGHT light. if you do it needs a motor. If not it could be a bad resistor block for the motor which it right next to the motor in the bottom of the heater box. As for the no frank sould like a bad conenction somewhere. these wre noted for batteries leaking acid into the cables if that were the issue you may have a corrosion problem between the battery and the cables. take the cables off and make sure they are clean if they are corroded at all baking soda and water will clean the acid off the cables. That is where I would start looking first. good luck :-)