Pretty cool...

[Chkn Sanwch]

So, a few weekends, the battery in my car kept dying and wouldnt hold a charge. We narrowed it down the a bad diode in the alternator. But anyways, while my dad and I were looking for the problem, we found with a volt-meter that my cooling system actually holds a electrical current of its own. The volt meter read .21 Volts on the upper radiator hose, and .19 on the lower one. My dad said that the entire system on these cars acts as a capacitor, so when the electrolytes in the coolant brush and flow across the various metels in the engine(aluminum, iron, steel, brass, copper, etc), itll generate a small, very low voltage current.

Never new that was even possible. I thought it was pretty cool, just wondering if anyone else has heard of this.

Matt

[A20A1]

Interesting... could it also be related to a thermoelectric effect? Peltier/Seebeck/Thomson

Where did you poke the probes at/on the motor to get the voltage from the cooling system?

[cygnus x-1]

What you are describing is a galvanic or electrochemical cell. Anytime you have different metals connected by some kind of solution you get a voltage potential between the metals. The radiator is likely brass or copper and the thermostat housing (for example) is aluminum. The coolant is the electrolyte solution. This is why radiators rot out if you don't change the coolant every so often or you use tap water that has chlorine and other minerals in it. The coolant becomes acidic and becomes a much better electrical conductor, speeding up the process (galvanic corrosion).

It's just like the classic potato/lemon clock science project.

C|

[ZackieDarko]

so this is why cars have a grounding wire coming off the valve cover

[Chkn Sanwch]

I touched the positive probe onto the upper radiator hose and the negative to any ground.

[MessyHonda]

yeah the more grounds you have the better it is. i have 3 upgraded ones

one from the valve cover...one from the alternator bracket and one from the negative terminal to the body