battery drain

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battery drain

Postby athenssprite » Tue Aug 19, 2008 6:16 am

Hi All,

I have '60 BE that's back on the road for a few weeks now :lol: Car starts every time provided I do not use the lights. Once I use the lights, battery will drain and most likely not have enough juice to start. Does this sound like a generator issue? Thanks.
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Re: battery drain

Postby Ragnars-Frogeye » Mon Sep 01, 2008 9:47 am

Hi athenssprite ,

there may be a short circuit in your light wires. On my Sprite the red wire (position light an d tale light) burnt of under the facia. The lights were still working. I recognized it as I was looking for my bad working indicator lights. So inspect all the light wires for burning or/and short circuit.
Another possibility could be the switch. Try to short circuit the wires without the switch so the lights are working and start the test.

Good Bye from Germany

Ragnar
Greetings from Germany

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http://www.ragnars-frosch.de
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Re: battery drain

Postby hoggie » Mon Sep 01, 2008 10:19 am

A good method to check for incorrect battery drain is to pull a battery cable and put a volt meter between the battery post and the disconnected battery cable. With everything turned off, you should not have any voltage.

So to check for incorrect leakage when the lights are turned on, connect the volt meter as mentioned and turn on the lights. (Ignition switch off) You should see the full voltage on the volt meter. Now start unplugging light connectors, remove lamps, etc. When all the lamps are disconnected, you should have no voltage. If you have voltage, then its a matter of following the wiring diagram and unplugging connectors until you find the leakage.

Mike
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Re: battery drain

Postby Bugzy59 » Mon Sep 01, 2008 10:49 am

When I wired my bug, I miswired one of the beehive lamps. I had the ground (black) to the center pole and that caused a short. I rewired it and no problem. Fast forward a year. Got caught in a rainstorm and all of a sudden ammeter pegs on charge with lights on. Again, I had the license plate light miswired. The water enhanced the connection making the short critical.
Although not stock, I have a 2" smith's ammeter. It has been a great help - especially with a marginal charging system. http://www.spritespot.com/gallery/view_ ... t08_pr_209

I had a problem early on with the voltage regulator. It was not allowing a charge. It is a electrical and mechanical device. I cleaned the points and sprayed it down with wd40 and it loosened up and worked. By that time I had bought a new one which I carry around....
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Re: battery drain

Postby hoggie » Mon Sep 01, 2008 1:45 pm

I enjoyed looking through your BE gallery. Lots of work and the car looks great. I think the back end of the BugEyes is one of the best BE styling features. I wished they had carried that forward on the later Spridgets.

Just a question on your battery drain, with your engine running at fast idle, your generator should be charging the battery at about 13 volts. At least it should be charging more than 12.6 volts. It should still charge that rate when the lights are turned on. I guess the question is whether the wiring system is shorting out somewhere and pulling too much load, or the generator or control box is not up to the task. The Haynes manual has good details on checking out the generator and control box functions. Since you had trouble with the control box before, I would suspect a problem, maybe corroded contacts. The generators seem to hold up pretty good as long as the brushes and armature are in good shape. My Midget has over 105G miles on the same control box and generator. I just replaced the brushes and cleaned the armature during my current engine rebuild, but the original brushes still had a lot of carbon left. The only charging problem I ever had over the life of the car was caused by the factory not cleaning the paint off the slide on generator connector and a radio on-off switch capacitor that shorted out causing the battery to slowly discharge while it was not running. Thats pretty good for 1950's designed Lucus electrics. I don't think I have ever had a car that made it to 100G without replacing the alternator.

Mike
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Re: battery drain

Postby Bugzy59 » Mon Sep 01, 2008 3:02 pm

Athenssprite:
Measure the voltage with the lights off. I think mine was 13-14. Measure the volts with the lights on. If there is a large drop, then you probably have a short. The bug has a front and rear harness. To isolate the short (if there is one), first disconnect the front harness then measure the volts with the light on. If you have more power, then the short is in the front harness. Do the same with the front connected and the rear disconnected.

Once you narrow it down to the harness, you can trace the wires and check the wiring of the lights. You can also try partially connecting each light to see which light causes a reaction.

Or you can use an ohm meter to determine which wire has a short. Ground one end of the meter then check each wire until the needle moves to show no resistance.

Believe it or not, this goes really quickly once you get started.

As Hoggie points out, the control box could also be a problem. viewtopic.php?f=3&t=3061
This thread discusses some of the issues I went through. I read the web site referenced by Charlie and learned about control boxes. I recall you can increase the voltage level by adjusting the set screws. FYI if the control box clicks on and off, then it probably is working.

Lastly, Smiths has a 2" voltmeter as well as an ammeter in case you decide to add a gauge.
Erik
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