Electrical Draw
Thread Starter
Pro
Joined: Jan 2006
Posts: 738
Likes: 5
From: Albuquerque NM
Electrical Draw
I have a 1971 convertible, 4 speed, that seems to have an electrical draw coming from somewhere because if I don't disconnect the battery, it tends to get run down. I just put a new battery in the car and am afraid to leave it connected when the car is not being driven.
I recently bought the car from my brother and he seems to think it's the brake switch (?).
Does anyone know how to test to see if that is the cause and where would the brake switch be located and what might it look like?
Thanks for any help you can provide!
Rich
I recently bought the car from my brother and he seems to think it's the brake switch (?).
Does anyone know how to test to see if that is the cause and where would the brake switch be located and what might it look like?
Thanks for any help you can provide!
Rich
Melting Slicks
Joined: Sep 2010
Posts: 2,371
Likes: 59
From: Emerald Isle NC
Use the Carl Childers method...check the easy stuff first. Start with the battery mains first, especially the ground cable. Remember, just 'cause it looks good, doesn't mean that it is. Get a good test meter, they can be found cheap, and be methodical in your troubleshooting. Haphazard troubleshooting procedures will result in nothing but frustration and wasted time...
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,112
From: Crossville TN
Pull all fuses from the fuse panel. Install an ammeter between the positive terminal on the battery and the positive battery wire. {It should be set to a 5 amp scale or higher.} Install the CTSY fuse last, so you don't have the draw from the interior lights confusing your readings.
Install one fuse at a time and look for significant current drain on the meter. With your key out of the ignition, you should see no needle movement when a fuse is installed. Once you see the ammeter show a reading, that is the circuit with the 'drain' (short?). You will have to 'fine tune' this process to isolate the area in the circuit causing your problem.
Note: DO NOT terminate your process just because you find a circuit having a drain. That current draw could be coming from more that one circuit or it could be a short between circuits. Check them all---then go back to isolate the fault within any circuit(s) that show a drain.
When you get to the CTSY fuse, pull the interior bulbs first to see if there is a drain with no bulbs in the circuit. If none, you can put the bulbs back in, then push the door jamb switch in to turn off the bulbs. Look for drain in that mode too. Good luck!!!
Install one fuse at a time and look for significant current drain on the meter. With your key out of the ignition, you should see no needle movement when a fuse is installed. Once you see the ammeter show a reading, that is the circuit with the 'drain' (short?). You will have to 'fine tune' this process to isolate the area in the circuit causing your problem.
Note: DO NOT terminate your process just because you find a circuit having a drain. That current draw could be coming from more that one circuit or it could be a short between circuits. Check them all---then go back to isolate the fault within any circuit(s) that show a drain.
When you get to the CTSY fuse, pull the interior bulbs first to see if there is a drain with no bulbs in the circuit. If none, you can put the bulbs back in, then push the door jamb switch in to turn off the bulbs. Look for drain in that mode too. Good luck!!!
