1958 battery drain

[Lars Kneller 8246]

My 1958 Fleetwood has been draining the battery overnight. I have one by one pulled the various fuses and it still drains the battery. The battery doesn't drain if I disconnect it. Any thoughts as to what the problem could be? Thanks!

[signart]

While the battery is disconnected, did you measure the draw from the drain on your battery? Assuming you disconnect the ground cable only, leave the pos cable connected, measure the draw with your DC amp meter. Do this by connecting one lead to the neg cable and the other to the battery post.

[J. Gomez]

My 1958 Fleetwood has been draining the battery overnight. I have one by one pulled the various fuses and it still drains the battery. The battery doesn't drain if I disconnect it. Any thoughts as to what the problem could be? Thanks!

Lars,

The only way to correctly find the parasite drain is to disconnect one of the battery cables and connect an amp meter in between the cable and battery post, as Art stated above.   

If you see a reading on the meter start removing the fuses (the ones that are always HOT not switched) and see if the reading drops. You also have CB (circuit breakers in-line with the HOT) so you can find them or the main connections for them and disconnect the power lead.

The only items that are shown on the wiring as always "HOT" would be the clock, power windows and seat (if applicable), headlights, trunk light, brake light.

I would suspect that either the clock or the trunk light could be the main culprits of your drain "BUT" you would need to do the check.

Good luck..! 

[TJ Hopland]

If you don't have an amp meter you can wire a traditional light bulb inline with the battery cable.  Smaller loads smaller bulbs.   The bigger the draw is the brighter the bulb will light.    You can remote the setup too.   Doing it on the ground is usually best because if you short something basically you are just bypassing your test rig. 

[savemy67]

Hello Lars,

I would suspect your battery is in poor condition if the clock or the trunk light drained the battery overnight.  Is the battery fully charged, with each cell registering more than 2 volts?

If your battery is in good condition, and the parasitic draw is draining the battery overnight, you may want to check for a seat or window motor that is hot (temperature).  A faulty switch may be sending current to a stuck motor.  The motor can't rotate, but will draw current until a bigger problem ensues (fire).

Respectfully submitted,

Christopher Winter

[fishnjim]

You need to be real careful here and don't leave the battery connected again until you find the issue.
If the wiring has never been changed, there's a good chance you have a short or bad/corroded wire somewhere that's heating up and will eventually burn and cause a fire.   
My horn wire did that, a slow draw until it got hot enough and melted the relay and finally the fuse blew.   {The insulator failed on the horn contact allowing current.}
These cars were not wired to today's wiring standards, as they bundle smaller gauge wires on larger gauge fuses. (see electrical diagram)   I found partially melted wires in under the harness tape that you'd never see until they caught fire.   I re-wired the engine compartment, and plan to do the others, if I decide to keep.   
I use a battery disconnect when sitting in the garage.   It's not good for battery life either to pull it all the way down a lot.   
For reference, it would take about two weeks sitting for the clock to draw down to where it wouldn't turn over/needed charged.

[V63]

Trunk pull down often the culprit , I believe it has an inline fuse,  not in the block.

[Lars Kneller 8246]

Thanks for all the advice. The battery is fairly new but I've had to charge it up several times from dead. I will hook up the amp meter next weekend and see what I get. My trunk pull down is currently disconnected as part of the round cylinder, which appears to be pot metal, is cracked and thus it is not working properly (I do need a new one, if anyone has one). I have removed the trunk light bulb overnight and it still went dead. I also disconnected the clock fuse with the same result. All of my windows and the seat seem to be working fine, and again, when I disconnected the fuse overnight, the battery still went dead. The only circuit I haven't investigated is the headlamps, so that will be top priority next weekend. I have hooked up a battery disconnect.

[signart]

Keep a check on your battery voltage while it is disconnected, make certain your battery maintains voltage during the week (12.6 volts or better). It's no matter how new the battery is.
If you are satisfied the battery is not suspect in any way, I would start investigating the voltage regulator as stuck points in the regulator can put a big drain on the battery, even with key switch off. Unhook the VR and do a drain test.

[V63]

Might try and feel the cover of VR for heat

[PHIL WHYTE CLC 14192]

I read somewhere that a fault in the regulator box can cause a battery to drain. Worth googing that problem. I think, but could be wrong that if this happens it leaves a circuit open back to the generator and that's where the battery drains to. Assuming you've not swapped it for an alternator? A generator will run like a motor if you hook  it up .

[dn010]

Make sure your power window switches are centered. I've had a few of them get stuck in the up/down position and drain the battery.

[The Tassie Devil(le)]

Any major drain from the circuit breakers being constantly on, as in window switches sticking up or down, would really create some major sparking when replacing a battery lead onto the battery terminal.

It is surprising just how good at draining any battery is a low wattage light being left on.

Bruce.

[bcroe]

. If you don't have an amp meter you can wire a traditional light bulb inline with the battery cable.  Smaller loads smaller bulbs.   The bigger the draw is the brighter the bulb will light.    You can remote the setup too.   Doing it on the ground is usually best because if you short something basically you are just bypassing your test rig.

The series bulb is also favored by me.  Sticking an ammeter in there
risks blowing it if you make a mistake.  And you can wiggle or disconnect
things while keeping an eye on the dim glowing bulb. 

A small 193 bulb will detect any fault serious enough to run your battery
down in a short time.  I had a trunk light cause the problem when its
switch shorted out.  Pulling fuses may not get you there, you must keep
disconnecting things till the bulb goes out.  good luck, Bruce Roe

[TonyZappone #2624]

Many years ago, I had a similar problem in one of my '56 Derham limos.  One night, for whatever reason, I was sitting in the back seat with no garage lights on, and no lights on in the car.  I heard this mysterious buzz in the left rear armrest.  It WAS the power window button cycling, buzz then off, then on again.  Took it apart either replaced it or cleaned it and the problem was solved

[Michael Petti]

Check the glove box light switch. If the dorr is not adjusted tight enough it will leave the light on and you won't see it.

[Ohjai]

A Clamp on DC Ammeter is a great tool to troubleshoot shorts and unwanted loads.  Just clip it around the wire, no disconnecting wires.  Be sure it measures DC Amps, not just AC Amps.  Like the one below:


https://www.amazon.com/Auto-ranging-Digital-Clamp-Meter/dp/B001VGND88

[Lars Kneller 8246]

I hooked up a light bulb and it is lit up. I removed all the fuses one by one and it remained lit. Trunk and glove box bulbs are off. All the window switches are centered. Which is the best terminal on the VR to disconnect to see if it's the culprit. I did order a new one to be safe. Thanks again for everyone's help.

[bcroe]

A Clamp on DC Ammeter is a great tool to troubleshoot shorts and unwanted loads.  Just clip it around the wire, no disconnecting wires.  Be sure it measures DC Amps, not just AC Amps. 

I use a DC clamp on a lot here, to check out my solar panels.  However, the DC sensor
needs to be zero set, and drifts a lot, so it is difficult to get the resolution for small amps. 

Bruce Roe

[J. Gomez]

I hooked up a light bulb and it is lit up. I removed all the fuses one by one and it remained lit. Trunk and glove box bulbs are off. All the window switches are centered. Which is the best terminal on the VR to disconnect to see if it's the culprit. I did order a new one to be safe. Thanks again for everyone's help.

Lars,

You can start removing the "black" wire at the VR "BATT" terminal and see if that clear the drain. IF that clears the issue the drain could be the VR or the generator, so you would need to do more troubleshooting on each of this two item.

Good luck..!