97 taurus electrical problem?

I have a 97 taurus 3.0 Duratec v6 with 210,000 miles. I just bought the car. It runs good, but has a couple of issues.

1. The battery light comes off and on, as does the ABS and BRAKE light on the instrument cluster. I have checked the battery with my scan tool = 12.8 v before starting and 14.3 while running. When the BRAKE light comes on, if I hit the brakes hard - the light goes out. (I don't think it's the emergency brake switch), I've pushed the pedal down and wiggled the pedal and all the wires.

2. There is a low rpm stumble after the engine is warm while idling (in any gear P-N-D). It's a single miss every 10 seconds or so. There is no check engine light and no misfire notifications in the computer memory.

Is this the alternator? - I have drove the car over 200 miles, with lights, heater, etc running. It starts fine.

I have a 98 taurus and with 65000 miles the battery light would come on if the rpms got above 3500. I used a voltmeter and checked the voltage when the light came on and the voltage dropped. I removed the brushes from the alternator and they were badly worn along with the commutator rings. Replaced alternator and have not seen that light since.

Have you checked the level of the brake fluid in the master cylinder? This probably won't answer the mail on the ABS or charging system lights, but you could have more than one issue right now. If the fluid level is low, don't just top it off and assume that's fixed. The level is low for a reason. Either you have a leak or your brakes are worn sufficiently to drop the fluid level enough to set the warning light.

As for the charging system light, I agree with madnessinc, verify the charging system is outputting enough when the light comes on.

As for the missfire, are you just checking the datastream for misfire indications, or the Component Parameters (PIDS, CIDS, etc.)? You could have an intermittant misfire that will allow a cylinder misfire PID/CID, but not cause a P0300 code or even a misfire count in the datastream.

-Rod

When you check out the charging system, I would take the battery out and have it load tested somewhere. I had a problem with the battery in my escape. It would start fine, until one time that it wouldn't. Charged it back up to specs and started the car fine. Took the battery and had it load tested and it failed (voltage was fine), it had a dead cell in it. My ex's car (97 escort) had similar problems to yours and her's was a bad wire.