[quote name='sbdrivingdotcom' post='37835' date='Jul 4 2007, 04:58 PM']Today I jumped the car and drove it to a friend's house who has a charger and a multimeter. The battery had less than 7 volts and wouldn't power anything. In fact I couldn't even close the rear trunk lid without the car started -- apparently it is electrically controlled. While the engine was running the alternator was charging the battery with over 13 volts, so the battery appears fine -- checked at idle at the battery. With the car off the battery was between 4 and 5 volts.
My question is how could a brand new battery become so discharged in the span of a week? There were no dome lights on but the cab windows were down and the car was unlocked in the transporter. The driver said the keys were NOT in the ignition when the batter supposedly died.
Any ideas are welcome. Also, I can't get the top down. Can you only put the top down with the key in the accessory position and the car off? If so a dead battery would preclude the top from going down, right?
Also, the radio won't work and now the exclamation point dummy and airbag lights are on. Are these a factor of the dead battery? Thanks in advance.[/quote]
We got a Florida Cab as well (it had been a lease vehicle) and as far as we could tell none of the maintenance under the lease was ever documented. Some thoughts on your problems:
First it appears that your alternator is working, 13 volts at the battery while running may be a tad low, however we found that the dash gauge was running about a half volt lower that actual. The 13 volts doesn't indicate a good battery, only that the alternator was delivering 13 volts to the battery.
The trunk lid on our 95 Cab does not use an electrical motor to close, however there is an electrical solenoid that releases the lid. A couple of years ago after a fender bender, the body shop inadvertently disconnected the wiring to the solenoid and the trunk release no longer worked, except with the manual wire loop release. When electronically released the trunk lid on our cab pops up less than a quarter inch, turning on interior dome lights. If the release point is maladjusted, it may not even release that far. Not noticing that the trunk lid is actually open, has caused me more than once to run down a strong battery. Especially if it is daylight out and the dome light is not obviously on. I thought we had a malfunctioning door/dome light switch that was to blame for the dome light not going off when the doors were shut. More that once I have failed to notice that the trunk lid was actually opened and the battery discharged so much that I couldn't start the car. When the battery is discharged the dome light will appear off. Sometimes if it has only been a day or two, I can get the battery quickly charged and start the car (Sears international series battey)
You seem to have significant battery drain when the car is shut off and the alternator is capable of supplying power when the engine is running. You need to measure the current drain on the battey when the ignition switch is in various "off" positions, a multi-tester probably will not be up to the task as the drain may be well above the 500 millamp range of most multi-testers. Try disconnecting various electrcial circuits to see if the current drain on the battery drops. I'd try disconnecting the trunk lid solenoid first since it seems to want current to close, our trunk lid will close without a battery. However you can't open the trunk with a key since the trunk key lock is a switch to the solenoid and is not mechanically connected.
Since the top can be raised only when the engine isn't running, but in an on position, a shorted ignition switch could be sending current to the top when the engine is off, but this is less likely.
If it is the factory radio and the battery has been removed, the security code needs to be reset. If the code was improperly entered, the radio will be dark for longer and longer periods of time before allowing security code re-entry. On our cab the car had to be actually driven before the code on the CR-1 would reset. The last time it took more than an hour of actual driving over a couple of days. Also had to make more than one trip to the dealer to get the right " security code". I wrote the code on top of the radio case after finally getting the right one. I upgraded to a newer Becker Porche radio like many others have done but haven't gotten around to selling the old one on eBay. I doubt your radio is actually dead, but is in a security display lock out until it allows the next attempt to set the code. Even if it looks dead, you have to leave the radio on while driving or the radio will never reset and display "code". I doubt that the radio appearing dead is a cause of the battery drain, but merely a result of the battery being disconnected or discharged below the radio's minimum voltage.
-sp4149
