Electrical drain, battery won't maintain charge?

[36tudordeluxe]

I have a 12V negative ground electrical system system with alternator in my '36. Am told that I should not see sparks at all when hooking up battery cables; I do whenever I hook up the positive cable. I have two fuse panels, one for switchable accessories and one for circuits that remain hot. I have pulled the fuses one at a time for all circuits but continue to get spark at positive cable. where do I go from here?

 

[40cpe]

Take the feed wires off the fuse panel one at at time. Maybe there is a low grade short in one side of the panel.

 

[cas3]

unhook the alternator, check again for spark. if no spark, bad diode in alternator. modern radio's have a memory too, but thats a very small draw

 

[Barlea]

Hydraulic brake light switch can sometimes fail with the connection "made", but not able to pass enough current to light the bulb filaments.

 

[36tudordeluxe]

Take the feed wires off the fuse panel one at at time. Maybe there is a low grade short in one side of the panel.

Previously, couple years ago did have diode in alternator replaced when having an electrical problem, cable still sparks with alternator wire disconnected. What I did find was that when I disconnected feed from my 50 amp circuit breaker to the fuse panel that is hot all the time the battery cable no longer sparks. Yet, when I fail each circuit by removing the fuse for each circuit the battery continues to spark. So, are we talking about a "low grade" short here? It does take a few days to knock the battery down where it doesn't have sufficient voltage to crank and the spark at the cable is very slight.
What would be my next step?

 

[Kurt in NJ]

Do you have one of those "free" harboe freight multimeters??, they have a 10 amp scale
Some of the electronics that have 2 power feeds can draw when one is unhooked

stock cars have known componets, it is easier becauser the systewm in known, on modified cars only the person that modified knows what was done

 

[40cpe]

First I would disconnect the feed TO the circuit breaker and check for draw. If it still has the drain, go back toward the source at every connection until there is no drain.

EDIT: I didn't read your last post correctly. When you disconnected the fuse panel, the drain went away. So your circuit is good to that point. You either didn't remove the faulty circuit from the panel or the panel is partially shorted to ground. Remove the fasteners that connect the panel to the car and make sure that the fuse panel isn't touching the car's metal anywhere and recheck. If it is still has the spark you didn't remove something from the panel when checking previously.

More thoughts: Maybe you have more than one appliance in the car that has a memory draw. Try removing all the fuses from that panel at one time and see if you still have the drain.

 

[36tudordeluxe]

First I would disconnect the feed TO the circuit breaker and check for draw. If it still has the drain, go back toward the source at every connection until there is no drain.

Will give it a go tomorrow

 

[Paul Bennett]

When confronted by errant current drain, I like to remove all easily available battery connections and fuses then test - add back one circuit - test - add back another circuit - test ... proceeding a small circuit at a time.

Quite often the drain is beyond what you see as 'everything' which really isn't everything but is really your idea of everything so you become mislead and overlook the real problem. So if you simply remove a tiny bit then test you will miss the real problem or waste gobs of time finding the drain.

I like what someone suggested using the I or current metering on an electrical meter. If you aren't sure you know what you are doing, many are willing to show you, it's a good ability to know. Doing a hunt this way can go quickly if you have a 'meter watcher' to call out anomalies as you add back fuses etc.

Incidentally, common problems are bad diodes inthe alternator regulator and the radio.

 

[Kurt in NJ]

You can have a large seeming spark when hooking up the battery cable but the draw can be nothing when a capacitor in some electronics is charging---you need to use a meter to know how much of a draw

 

[WestCoast]

if you have a chevy one wire alt, they have been known not to break the charging circuit in the alt and it stays hot when engine is turned off, will drain batt over night

 

[36tudordeluxe]

if you have a chevy one wire alt, they have been known not to break the charging circuit in the alt and it stays hot when engine is turned off, will drain batt over night

Nope, it's a two wire alternator.

 

[Bored&Stroked]

Is all the wiring new and yours, or is some of it original Ford style? What are you doing for the main headlight switches and brake lights?

 

[Frank Miller]

If you disconnect power to the fuse panel there is no draw but the individual circuits disconnected do not remedy anything then I would look for a short in the fuse box.

 

[TJ]

Make sure something hasn't dropped behind the fuse panel (metal shaving, etc) and is causing the short. Or a wire has come loose from a contact and is touching another wire. Had this happen some years back with an aftermarket panel. Fond the problem after I removed the panel from it's mounting.u

 

[36tudordeluxe]

My two fuse blocks are made of plastic and our mounted to the vinyl covered kick panels, the mounting screws on the backside don't make contact with the metal bracing/reinforcement in the opening for the kick panel.
The power supply for my main circuit breaker comes from the post on the starter. On the other side of the breaker a line goes to the panel that is hot all the time. Another line runs from the power source post for the breaker to the hot side of the ignition switch. Then a wire from the switchable side of the ignition runs to the accessory fuse panel. Also, from the
switchable side of the ignition the wire to the alternator is located. Thought this might be useful info..

 

[V8COOPMAN]

The power supply for my main circuit breaker comes from the post on the starter.

You sure about that? That post would only be "hot" while starter is cranking engine. DD

 

[36tudordeluxe]

You sure about that? That post would only be "hot" while starter is cranking engine. DD

I should have stated that I have an aftermarket starter that has a built in solenoid, the post is always hot.
Also, I misstated the power source for the hot panel, it actually gets its power from the switchable/demand side of the circuit breaker.

 

[Old Henry]

Don't know if this would apply to your modified '36 but on my '47 I always get a little spark hooking up the battery because the electric self winding clock has unwound and the contacts are closed to energize the electro-magnet to rewind it. When I hook up the battery a split second connection that immediately opens shows as a spark. Could be as simple as that.

As others have said, you really need to check the magnitude of what you are thinking is a continuous drain with a meter. May be just something like the clock or a condenser charging that makes the spark but is not really draining. Even just a test light between the disconnected battery clamp and the post would show that without a meter. If it just flashes on then off - no drain. If it stays on bright - it's a definite drain.

If you're not sure about your battery, wouldn't hurt to have it checked. They do wear out.

 

[40cpe]

Since the spark goes away when you de-energize that fuse block, the source of the drain is in the block itself or one/more of the circuits from it. Have you removed ALL the fuses from the block (at one time) and checked for a spark? Have you put a volt meter between the battery post and the removed cable?