7 degree temps caused a hard start on monday,. would not start at first,. but after an hour its did but just as it did smoke rose out of the vents,.turned everything off it stopped,. restarted engine, heater off ,all was good,.drove the 10 miles to work,truck died on the off ramp and no juice to restart.after the jump turn sigs not working,.@work put in a new battery (we sell them) ,. motor started fine ,heater worked, fan worked,signals worked. 2 days later ,.truck dies going in to work again radio cuts of clock stops ect.,got a jump started and got me to work,.kept the truck inside ,. on the way home signals failed radio was in and out clock ect,. even the head lights began to give out,. today no power at at all,. pulled the heater blower motor and diode both had a smell of smoke removed any small pine needles but no sign of fire,. so would a bad motor & diode cause the battery to discharge like this ,. has this happened to anyone else ? is there more at issue,. keep in mind there were no issues till it was 7 degrees and this smoke apeared,. thanks Gunner
i failed to mention this is an 1981 351 2v auto w/ factory air that i've never had working

 

Sounds like you are dealing with a blower motor that is dying. You may have lost a winding or have a bad brush. Either way, the "cooked" smell from the resistor pack is a sure sign that the blower motor is drawing more than it should. If you are overheating one circuit running through the dashboard like that, its a good possibility that the ones around it will be affected as well. The recommendation would be to replace the blower motor and, if you can find one, the resistor pack. (overheating a resistor changes its resistance value). Once you have done that, check the wiring upstream of the blower circuit in the dashboard. If the wiring overheated enough, you could have melted insulation in the harness which will cause shorting and other failures later on.

 

replaced the blower motor,.resistor was in good order,.(tested it),.seems the blower motor did burn up drawing large amounts of juice charging on the engine was 9.7 volts before the swap,. and 12.9 after,.WOW,. i would not have thought that,. replacement motor was however a pain in that autozones replacement was for a later model (no matter what the box says),. so i had to clip and change the elect. hook ups,. not hard just a pain,.and the new motor did not come with a gasket,. andthe old would not come off,.figures,. so i just used some good RTV,. all is well,.thanks