i have a 67 coupe and was wondering if anybody knew where a ground off of my firewall, near the heater blower is supposed to connect,and could that not being connected cause a battery to drain

 

The ground that is attached to the firewall on my car is attached to the top starter bolt. It should not drain the battery. To find the battery drain take the negitive battery cable off and put a test light on the negitive side of the battery and the other end of the test light on the negitive battery cable and if the light comes on there is something left on. A clock and the radio presets will have the light on but very dim but if the light is bright. Start to pull the fuses out untill the light goes out and that is the drain from the battery. So that fuse is the problem, look in the manual to see what fuse is the problem. If there is no drain from the battery check the alternator and the regulator. To check that use a multimeter to check the voltage it should be between 11.5 to 13 volts when the car is off and when the car is running it should be between 13 to 15 volts. If it is the same when the car is off and on there is something wrong with the alternator or regulator.

 

Actually if you are getting a power drain while the car is running down the road, like the altenator is not charging then the answer is yes. Becuase the block is not grounded to the chasis you will have a differnece of potential. Now that being said the altenator has its own ground and the block not being grounded properly should not affect it. But I have seen cases where it has. The cheap fix is properly ground the block and then see if the battery still drains.