Zeus

It's been pouring here lately and due to the fact that Tucson is the single worst designed city in the entire continental United States of America, we have enormous pools of water 4-5" deep on every single major street.

I was driving along the main road last night going about 35MPH and hit one of these puddles. I'm assuming the water splashed up onto the bottom of my engine because I instantly started having problems:

1) My 'ABS Inop" light came on
2) My "Airbag" light came on
3) My "Brake" (parking brake) light came on and started flashing
4) My voltometer pegged the limit at over 18V

I figured everything was just a little wet and needed to dry out so I went home right away. I also checked the fuses under the hood and couldn't find any blown ones. Anyways, I go to start the car again this morning and the lights have gone away, but my alternator is still pegging the voltometer. What could cause this?

I know that the voltometer is not broken because my fuel pressure is up a few PSI and the lights in my cockpit are all brighter. I thought maybe it had something to do with the excitor wire, but IDK.

Bill's 02 Z-28 SS

Hi
Disconnect the battery from the system and measure the voltage of the battery. At 24V your battery should hot and cooked. I don't know how your alternator could be putting out 24v unless the diodes blew in some weird way. Get a real meter to measure the voltage, don't go by the volt meter in the car - you could have blown something and getting the wrong readings. I would not drive the car until you checked everything out. You will cook everything in the car at 24v.
Bill

2002_Z28_Six_Speed

iTrader: (19)

I don't think it is possible for the alternator to put out that many volts.

(I thought the voltage of the alternator was determined by the magnetic field passing through the core of wires so basically RPM of alternator shaft makes the voltage. How could it be spinning that fast?)

Zeus

I have a Fluke DMM I'll run across the terminals in an hour or two, but based on my voltometer the car's running well well above the ~15V it normally is at.

Zeus

OK I just put my fluke across the terminals and started the car. The voltage was rising rapidly and I shut it down after it hit 18V. Something is definatley not right here.

Any suggestions?

Phoenix 5.7

iTrader: (7)

it could be that the system isn't running at 18+, but instead its the sending unit

Zeus

I don't know if you caught my post above or not, but I just measured the voltage with a Fluke DMM across the battery terminals and it was climbing passed 18V when I shut it off.

Phoenix 5.7

iTrader: (7)

alts do have internal voltage regulators, could have fried it

Bill's 02 Z-28 SS

Hi
OK - I am glad to see that you measured the voltage with a Fluke DMM, that is good but 18V is not. That is very high, I would expect that the ALT would put out around 15V. I would take the ALT off and have it tested at Auto store - most places can do that for you. It sound like an ALT problem. What was the voltage of the battery without the engine running?
Bill

Zeus

12.7V, right around where it should be.

Bill's 02 Z-28 SS

Hi Zeus
Again the ALT sounds like your problem - the battery voltage is feed back into the alt for it to work. I will check my shop manual and let you know what it says.
Bill

SmokingWS6

iTrader: (1)

I'd go ahead and pull the alternator before it cooks your electrical system. The voltage is internally regulated, it sounds like the regulator was damaged by the water. After you replace the alternator i'd look into replacing the battery, I'm certain the battery has been damaged by now after accepting that voltage

Zeus