I have a 1999 Ford Taurus that is possessed. My battery is being drained overnight. I replaced the battery, the alternator, the negative cable, have removed and cleaned and SCUFFED up the negative grounds on the vehicle. We have with a multimeter checked the fuses both under the dash and the hood. NOTHING! At times the windshield wipers come on without being turned on, the tacky goes to zero, the speedo goes to zero, and eventually dies but after a boost off it restarts allowing me to get home to put on battery charger. Have checked the alternator and battery both good. Now the darn thing will not come out of park! While attempting to repair this we found the brake lights out so we replaced the bulbs but NOTHING, and still will not come out of gear. Could all these symptoms be related to the charging problem or could the lack of brakelights be the cause of the charging problem? The alternator is putting out exactly what the battery is discharging approx 26.. HELP SOMEONE PLEASE!! :confused:

. Charging problems may indicate a problem with the voltage regulator or PCM. 26 volts is way too high.

. The link below may give you some ideas:

https://www.askmehelpdesk.com/cars-t...tml#post258005

Check the PRNDL switch on top of the transaxle--it's a high wear item and you'll see a control linkage going to it. Also, check the ATX interlock switch, whereby you need to depress the brake pedal for 5 seconds first. The switch may be bad.

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Originally Posted by catscrazy3

I have a 1999 Ford Taurus that is possessed. My battery is being drained overnight. I replaced the battery, the alternator, the negative cable, have removed and cleaned and SCUFFED up the negative grounds on the vehicle. We have with a multimeter checked the fuses both under the dash and the hood. NOTHING!! At times the windshield wipers come on without being turned on, the tacky goes to zero, the speedo goes to zero, and eventually dies but after a boost off it restarts allowing me to get home to put on battery charger. Have checked the alternator and battery both good. Now the darn thing will not come out of park!! While attempting to repair this we found the brake lights out so we replaced the bulbs but NOTHING, and still will not come out of gear. Could all these symptoms be related to the charging problem or could the lack of brakelights be the cause of the charging problem? The alternator is putting out exactly what the battery is discharging approx 26..HELP SOMEONE PLEASE!!!!:confused:

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Sounds like you have a 'parasitic' draw(like the dome light being stuck on for instance). You need to disconnect one of the battery cables(doesn't matter which) and put one of your VOM leads on the battery terminal and one on the undone cable. There should only be millivolts draw, if there is significant draw go along and unplug each fuse in the box until it goes away to see what circuit its in. Then take it from there...
PS: I didn't see the 26 volt reading you wrote---dang that's high, Tex is correct! Most likely the voltsge regulator has failed, I have seen THAT allow the battery to discharge with the engine off.
Hal

Thank you for your response. Checked all fuses NOTHING. Bench tested alternator found nothing wrong. Regulator fine. Any other suggestions?

Check the PCM (computer).