Technical Has anyone heard of or experienced 'stray electrical current'?

Stray electrical current can destroy aluminum or
copper/brass radiators if gone unnoticed. A good
example of how radiators are so vulnerable to stray
current corrosion is that many of them are attached
to the vehicle by their plastic tanks, or are insulated
from the vehicle chassis by rubber mounts.
In some cases electrical cooling fans are mounted
directly to the radiator frame. Fans and fan motors
cause lots of noise, vibration and harshness so
they are insulated from the vehicle on rubber
mountings. Introduce some bad electrical contacts
for the fan wiring and we have set the scene for
rapid electrolysis via the cooling fans.
The same fan is probably cycling more often because
it can’t rotate quickly enough as it has a bad earth
contact. These are perfect conditions for disaster –
lots of stray current, longer fan ON time and a hotter
engine. A copper/brass radiator will suffer stray
current damage, However, an old copper/brass
radiator is usually bolted directly to the vehicle body
work, providing an easy path to earth for any stray
current that finds its way into the cooling system.
Plastic tanks and rubber mounts deny any stray
current an easy path to ground. The environment
for electrolysis in its most virulent form now exists.
Cooling fans are by no means the only cause of stray
current problems. Stray current problems can occur
following body repairs. The cause is over-spray. Paint
does not conduct electricity. Therefore, over-spray at
an earth point forces the current to find an alternative
path to earth – usually via the cooling system.
Corrosion damage in the areas of a radiator, while
operating within a squeaky-clean cooling system, is
a pretty good indication of stray current damage.
In simple terms, stray current is a chemical/
electrical process which causes an electrical current
to pass through a vehicle’s cooling system fluid. It can
cause rapid damage to radiators and will indirectly
cause problems with other engine components such
as water pumps, thermostat housing etc.
Stray current corrosion
in cooling systems
It occurs when one or more electrical items, such
as a cooling fan or headlights, develops a problem
in its electrical circuitry. This causes an electrical
current to seek out an earth path via the radiator
core through the engine
Check Procedure:
Note: This check procedure is best carried out with
plain water in the cooling system, since coolant may
give a false reading.
1. Remove the radiator cap and run the engine to
operation temperature. Do not rev the engine as
this may cause the coolant to aerate.
2. Switch ON all electrical items including items.
3. Switch a multimeter to a scale of 5 volts DC
or less. Ideally the meter should be capable of
reading milli-volts. A digital multimeter may not
be suitable for this test.
4. Place the negative lead of the multimeter on the
battery negative post.
5. Dip the positive lead into the coolant without
touching the filler neck or the core of the radiator.
6. A reading of more than .05 volts indicates the
presence of potentially damaging stray current
passing through the coolant. Ideally the voltage
should be 0 volts, however it is highly possible
that some voltage level will be detected.
7. If no voltage or a very low voltage is detected,
carry out the same test as in point 4, but with
the ignition OFF.
8. If voltage is detected, isolate the circuit by
turning all electrical items OFF and switching
each circuit ON individually.
A final note of caution: Refilling a cooling system
with recommended coolant will itself generate a
current that lasts approximately 12 hours.

 

Stray voltage is something that happens to cows in a barn, because of poor grounds on the electrical service. It can be fatal to the cow.
Ground your radiator and install a zinc anode in the coolant! After doing this you will have time to worry about something important. LOL

 

OK! I'm thinking wire a chunk to the bottom of the cap?

 

You may be correct about "stray current"....but my understanding of electrolysis is that it can and does occur without induction of electricity from an outside source. It occurs through 'dissimilar metals' reacting when immersed in a liquid and a current is generated through 'galvanic action', resulting in corrosion. That's my story and I'm sticking to it..

Ray.

 

Had the sleeve come apart in the diesel engine of an IH 915 combine due to electrolysis. It was the first time I heard of it. $8250 later it was up and running good, IH did add a filter to the cooling system that they said eliminated that problem. That was back in the early 80's.

 

My brass/copper radiator kept getting small corrosion hole in it. The radiator bloke fixed it each time and then asked how it was mounted. When I told him it was rubber mounted he got me to bring the vehicle in for a look. He stuck the multimeter probes inside the coolant and it had electrical current in the coolant. He poured some goop in the coolant and I haven't had a problem since. It's been 3 years. I also have put an earth from the radiator to the chassis.

 

There is some stuff called Penncool (sp) that is used in "big truck" radiators to keep the PH correct, good parts stores should have it

 

This. Chemicals have been added to coolant to combat it. Cooling system filters aren't so much filters as they are a way to release the chemicals into the coolant.

 

Stray electrical current. you mean like being struck by lightning stay electrical current?

Aside from electrolysis from unlike metals and liquid you can also develop static electricity just from the movement of the coolant. Anything in a vehicle needs to be grounded. I even like to run ground straps (those hangy down things) on my stuff because of static.

 

I experience it every time I run a comb thru my dry hair..LOL

 

YOU HAVE HAIR!!!!!!!!!

 

I had this problem in a vehicle with a 302 small block. If you use an analogue volt meter and connect the earth wire to a good ground on the car and put the positive terminal in the radiator water you can check if there is any stray current.
It wont show up if you have antifreeze in the system.
I couldn't work out why I was having corrosion problems with my aluminium manifold until my neighbour came over for a visit one evening.
He is a well respected local radiator man and he explained the problem I was having could be a stray current.
We got the car up to operating temp and he had me turn every switch in the car on and off so he could check the water for any current.
As soon as the electric fan started there was a small current detected on the meter. I then asked why he had asked me to turn all the other electrical things on and off and he said you can get the same problem with a bad earth on other electrical items on the vehicle.
I still don't understand it but the problem went away after making sure the earth straps I already had there were infact contacting bare metal and not paint.
Wayne told me he has seen new alloy radiators eaten away very quickly so the problem cant get serious pretty fast.
You must use an analogue meter not a digital one.
If you Google it there is heaps of information.
Cheers
Peter

 

Interesting and eye-opening subject. Thanks for bringing it up, Mike. I've always said you can't have too many grounds.

 

Had stray current in my OT SUV, alloy radiator with plastic tanks developed slight pin holes for no apparent reason. Radiator guy said it was stray current. Don't assume an earth lead to the radiator will fix it, the lead sometimes increases the current. I still have the technical data sheet and it surprised me. Mixing coolants with different chemical compositions can lead to a residue that needs flushing with an alkaline cooling solution. A new radiator with a complete flush and all new coolant fixed the problem.

 

One 50-cent phrase from the Corrosion fellas was 'differential oxygenation' !
I took this as meaning 'air' gets more easily to the region undergoing corrosion...it becomes the system's designated anode. Distilled water would appear to have fewer 'ions' floating in it, but I'd bet it still has 'dissolved oxygen.' Something; is carrying a current between any two regions/metals...who disagree about their relative 'Nobility.'

 

Chrysler had a problem on some models in the mid-70's where someone decided they could run the ground side of the battery to the engine and that would serve as a sufficient ground circuit for the entire car without having either a ground from the battery to the chassis or a ground strap from the engine to the chassis. Theory being everything would be adequately grounded thru other connections from the engine to the chassis via the drivetrain, etc.

Thousands of cars across the country started developing water leaks from corroded freeze plugs. The warranty repairs cost $$millions since the fix required pulling the engine to replace the freeze plugs (and adding a ground strap that would've cost maybe a dollar if it had been put in originally). They also had to recall the sold cars that weren't leaking to add the ground strap as well as adding it to all the unsold cars that were in the inventory.

A guy I worked with in the 80's had worked in engineering at Chrysler during the 70's. He said the problem was complicated by more than a few shady dealers who would add the ground strap, dump a bunch of stop-leak in the coolant system, and then bill the company as if the full warranty repair had been done.

Just about the time when the company figured they'd completed the repairs on everything in the field, a 2nd wave of coolant leaks started showing up, made up mostly of cars that had been "fixed" by stop leak.

 

PnB: Stray electrical current. you mean like being struck by lightning stray electrical current?
Beaner, he might have meant currant(s) those pesky little raisin substitutes in a fav. recipie. W/straps, least you won't be hit by lightning!

 

I've owned tires that generated a lot of static electricity (not that that would rot a cooling system). Had a car that shocked me every time I touched the door handle to get in. Changed the tires--- static went away.

Heard stories about cars that suffer from run-on after shutting the ignition key. Turns out the electric fan was still spinning when the key was shut, the fan was generating electricity and back-feeding the ignition circuit.

Yes, a cooling system can chemically generate electricity even without an outside source like an electric fan or static electricity. Take dissimilar metals and add an acid and you've basically created a wet-cell battery.

 

Fact sheet #119 at this link. Credit should be given when copying text.

http://www.nulon.com.au/support/factsheets/

 

x2, copyright Ebbspeed.

 

Electrolysis can occur anywhere. I used to work on elevators and we had hydraulic elevators where the cylinder and piston were 30 feet underground.
Eventually some of the cylinders were leaking oil from pin holes caused by electrolysis.
Now days most hydraulic elevators have the cylinder and piston in the elevator shaft.
Looks like a big fork lift truck...

 

We have had stray currents run thru our backyard. When possible, we put a leash on them & call the electric cops.

 

Your not right! Pete

 

Why do you not run antifreeze?

 

Not car related but we had a problem at our restaurant with pinholes in copper water supply lines. After several repairs and a lot of head scratching I found a spot in the ceiling where the copper line was in contact with galvanized steel framing material. I slipped a length of foam a/c line insulation over the copper water line and the problem went away.

 

OK, I guess. But what happens when ... . . .. Oh, never mind. I don't really want to know.

 

My girlfriend has a Ford Ranger with a 4 cyl. At 64000 miles she developed a drip in the engine
that seemed to leave a spot under the car but she could never find. One day the truck started to
run hot on the highway so she pulled over and called me. By the time I got to where she was a
State Police Officer had stopped and called a tow truck. They took the truck to their shop and
decided it was a bad t-stat, and changed it. She got the truck back a week later along with a
$350 bill, and a cracked t-stat housing that they silicone to seal.

The truck still dripped, so she brought it into the dealer her Dad was a salesman for. They found the
cracked t-stat housing, replaced it, and ran the truck to check it. There was still a leak, it seemed to be
at the rear of the motor so the tech reached behind the engine to check where the leak was. His finger
went right thru the block!

The service manager called Ford. Since she had had the vehicle serviced since new at the dealer when
Ford claimed failure to follow the recommended service that did not fly. They finally said their was
some kind of ph imbalance in the cooling system, since it was Ford recommended Antifreeze in the
truck they finally agreed to replace the engine if she paid the labor even though it was out of warrantee.

The truck was constant problems with the cooling system, heater core etc. I was not sorry to see it
totaled by the insurance co when the truck hit a guardrail during a snowstorm. I am convinced it was
an example of currant leakage causing the cooling system to eat the metal away.

 

I do run antifreeze but I was told the stray current would not be detectable when antifreeze was present. So I flushed the motor and did the check with just water then afterwards put in new antifreeze.
I know it sounds stupid but I was following instructions from somebody that took the time to help me and I didn't question him.
I hate car electrical crap this is a perfect example of why.

 

electrolysis damage to aluminum intake manifold

 

Will these steps eliminate the problem?

Ground strap from radiator to frame

Electric fan, if used, ground to frame.

Engine ground to frame

Battery ground to frame

Body ground to frame (rubber mounts)

All grounds on clean metal with dielectric grease.

I have a car in primer, much easier to weld on some nuts now for future grounding.