Testing For
Electrolysis
"Simply attach the
negative lead of the voltmeter to a good grounding point on the engine, and dip
the positive lead into the coolant..."
Can Electrolysis be measured? At the heart of any electrolysis
discussion is it's measurement. If it can be measured, it's presence
can be verified, which is extremely important when we are
classifying, treating, and removing the electrolysis.
To get started, lets take a couple of simple measurements,
with a digital VOM (volt/ohm meter).
1) Simply attach the negative lead of the voltmeter to the
engine block, or other known good ground, and with the
positive lead, dip it in
the coolant.
Unless you read zero, you have
electrolysis! If you measure less than .1v, your cooling system
should
be below the action level. If you measure .3v or above, keep
reading.
2) Next, repeat the test with the positive battery cable
removed.
Still reading .3v or above? It's not a loose ground
your after....the voltage is coming from within, and you most likely
have
Type B electrolysis.
If your voltage dropped when battery was
disconnected, you most likely have
Type A electrolysis.
Type A may be isolated to a switched circuit, and must be isolated
in much the same manner as finding a voltage draw: circuit by
circuit. It may just be a loose or missing ground. It may be much
more.
Regardless, if you have a reading of more than .3v, (three tenths),
you have damaging electrolysis. Generally, a reading of hundredths
(.01-.09v) is below the action level, and will not result in
aluminum failure.
Summary of Testing
| No Voltage Detected |
Take no Action |
| Voltage reads .1v or above even after battery cable(s) removed |
Type "B" electrolysis,
Go Here |
| Voltage reads .1v or more, but
reads 0v when battery cable(s) removed |
Type "A" electrolysis,
Go Here |
