420A Battery Light

[DiamondStarMotors]

Battery light came on. Charged my battery over night, today I drove 50+ miles came home check the voltage. 11.88 while running and 12.1X while off. What's up with that?

 

[Blue Talon Boy]

Ok, number one. My battery has not died yet, I had charged it over night just to be safe because i didn't have a voltmeter with me at the time, I got home after a 50 miles trip and two different meters read around 12v, Radioshack analog and a high end (name begins with an F) digital one. I felt my way past the splash shield down there and the belt was on there pretty good, it was there and not loose anymore than it should be.
Number two, I have a OBD-II to USB cable and a program that reads CEL and different "telemetry", if you will. The program did not read any codes.

Hopefully this information helps clear up some "ideas". Knowing DSMs, it wouldn't surprise me that the powersteering would use a different light. My coolant light went away not after I added, water/antifreeze to it. It went away after I pulled my sparkplugs and cleaned them up, meaning the top and the bare metal parts with electron cleaner.

I love these cars, but man are they a hassle.

The reason you were reading about 11.88 v running and about 12 off is there is no charging going on. You should be seeing better then 13.5v at idle with a good alternator. The coils in the alternator are shot or nearly so. Replace the alternator and call it a day.

Of course you didn't have any DTC's, a bad alternator isn't going to cause a CEL.

Ps, high end meter is a Fluke brand.

Power steering? Really? :facepalm:

 

[GRAVEDIGGER]

The reason you were reading about 11.88 v running and about 12 off is there is no charging going on. You should be seeing better then 13.5v at idle with a good alternator. The coils in the alternator are shot or nearly so. Replace the alternator and call it a day.

Exactly! Time for a new alternator. If it doesn't have 13.5-14.8 volts with the engine running it is junk.

 

[DiamondStarMotors]

The reason you were reading about 11.88 v running and about 12 off is there is no charging going on. You should be seeing better then 13.5v at idle with a good alternator. The coils in the alternator are shot or nearly so. Replace the alternator and call it a day.

Of course you didn't have any DTC's, a bad alternator isn't going to cause a CEL.

Ps, high end meter is a Fluke brand.

Power steering? Really? :facepalm:

for some reason I was thinking fluge

Probably is a bad alternator, I should have had a dead battery after 50 miles

 

[KewlWinter]

In most cases it is the alternator in the 420A cars. It is a very bad design prone to failure. Making matters worse from a diagnostic standpoint, it is not uncommon to get 1 or 2 bad AutoZone remanufactured alternators right out of the box, so be prepared to bring 1 or 2 back until you find a good one if you go that route. Or get one from a reputable vendor that has been upgraded to higher amps and beefier internals.
In some rare instances, the ECU has been found to be the culprit. As stated earlier in this thread, it controls the voltage regulation.