TOPIC: Radiator Ground Issues?

It was brought to my attention that grounding the Radiator Fluid via a wire to the negative battery terminal can aid in fuel economy. There's even a YouTube video of it.

However, I recently got a warning from a local auto parts employee(I know, their word isn't always right) However, they brought up a good point that made me question the safety of doing such a mod.
He mentioned that electrolysis could damage the radiator.

I looked into it a bit and came to this site: Frequently Asked Questions about Heat Exchangers
which explains the concern.


Here's an excerpt from the above link telling of the danger & why.

"electrolysis in a radiator or heater is the localized degradation of the metal caused by excess electrical current flowing through the cooling system’s liquid coolant or metal transmission lines in search of an electrical ground. But what happens when there is no ground to be found, or an ungrounded electrical device in the vehicle creates excess electrical current?

Electrical current can be introduced into the cooling system in many ways, but some common causes are loss of ground due to mechanical damage or corrosion, or a frayed electrical wire coming in contact with the radiator. Any vehicle with accessories (such as driving lights) using the radiator as a ground is begging for an electrolysis problem. For body shop personnel, failing to see or detect a ripped ground wire or forgetting to replace one or more ground wires can cause electrolysis that won’t show up until months after your customer has left your shop with a repaired vehicle. Proper grounding is the key to avoiding the occurrence of electrolysis and, should it occur, grounding can be the key to diagnosing the root."

Likewise, some claim it prevents electrolysis. Personally, I'm confused.

What do you Gadgetmen think about this?

Well JV If you're concerned, check for any loose ground wires/connections under the hood. Go thru the procedure outlined in this post from G&M Radiator to see if there is any stray current in your coolant. Has this car ever been in a collision? You mentioned this car has had electrical issues before; I would now look for evidence of body collision repairs.

Bad grounds are a bane to vehicles, so thouroughly look for ground wires and clean the connections to ground. Scotchbrite pad, steel wool, whatever is handy. Be sure the body/frame connecting ground leads from batt. neg. cable are intact and clean at connections. You can always, if your batt. neg cable uses a bolt to clamp onto the batt. terminal, add a ground wire run to any convenient body/chassis connection point. 10 or 12 gauge wire w/ loop terminals crimped on the ends has worked for me many times. I will sometimes just add another neg. batt. ground wire to a body connection to ensure a good return path to ground.

If you have a plastic tank radiator and there IS stray current in the coolant, then the G&M gig should help you determine the source. You could add a ground wire for radiator but it would need connected to metal radiator core somehow.

No harm in ADDING ground wires. I don't see any gain in MPG or performance here, just preventative maintenance.

Take your DVOM put Neg.lead on Neg. batt. post. Probe around batt. exterior working towards Pos. post w/ Positive lead. If you see voltage anywhere except Pos post, clean the crud off batt. case and check again. Batt. crud will form conductive path thru the crud between the posts! Clean the Crud! This conductive path will worsen batt. condition, it's a short circuit, will shorten batt. life, and add work to the alternator's load.

Clean the Battery crud, check/repair and add Grounds as needed. Just good maintenance!

TracyG Gadgetman Reno

Ive grounded my radiator to negative bat pole drove a few 1000s km with no probs.
I disconnected it just before selling it.

if the cooling water is connected to ground by flowing thru the engine what would it matter if the radiator is grounded to? I mean its allready grounded thru the coolant. to get electrolisis you would want to connect it to the possitive pole and then you would probably se firework hahah
Im no expert but thats my opinion.


ps did you know, try this, take a spark plug wire off the plug and ground it to the rubber hose with a gap and see the spark jumping on to the rubber. that is supposed to be non conductive, any ideas on why this works

I'm not an expert either but, I have to agree with you. I thought the very same thing when warned about electrolysis of the coolant. How can it be possible without a postive?

The more I learn, the more confusion seeps in right along side it.
Ignorance can indeed be bliss sometimes. Unfortunately

Hi All, with regard to the rubber and the spark jump...

Rubber is NOT non conductive, it merely has a high resistance compared to other products.

They use the "Carbon black" primarily for coloring, with tires more so (to get the black tires).

If the voltage is high enough it will ultimately cause a tire to overheat and explode.

Plastics and rubber manufacturing 101

Karl Fortner
Tacoma, Washington

aha, i thought it was cause there was water inside the tube, Im going to try it on another rubber part with no water in it and see. will be back with my findings. tanks karl for you info and patiance