Electrolysis, stray voltage, bad grounds, the "Big 3" and more... | Ford Explorer Forums - Serious Explorations

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Electrolysis, stray voltage, bad grounds, the "Big 3" and more...

Fredness

Elite Explorer
Joined
June 2, 2000
Messages
664
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City, State
Tejas!
Year, Model & Trim Level
'05 Sport Trac Adrenalin
So, the Sport Trac is 5 years old, but we've had it for a year. After a failed left front hub, and the trans going south, I've decided to start from scratch with the maintenance/routine.

So, fluids were first.
The oil, trans, transfer case were recent, now the coolant.
While testing, I noticed that the reservoir was full of "gold" (Motorcraft Premium Gold-ish), but the radiator appeared to be clear. It felt like coolant (viscous/slippery), but the color seemed off. When drained, the radiator was VERY light green, like cheap old school coolant.

This frightened me, knowing that the "Gold" isn't supposed to be mixed; I decided to flush the system and change the coolant. I used a multimeter to test for stray AC voltage between the coolant and the block. On the Focus, it was .172v after 5 years. Good, but I decided to flush the system to change coolant. Now, the Sport Trac was .3v - indicative of electrolysis. This can eat a heater core or radiator in as little as 7 days (.5v or higher).
Since I found some research that suggests it could be a ground issue, I thought I'd check. The Focus (as a control) was ~2 Ohms from Battery to Chassis and ~3 Ohms Battery to Block - acceptable.

The Sport Trac? How about 5 Ohms to the Chassis and 25 Ohms to the Block? WTF?
O.K., something's up, let’s check some other points, like the shield for the PCM harness, that should be 2-3 Ohms, right? How about over 40? The PCM to Chassis Ground? 63 Ohms!!! Wow...

So, now we know something’s wrong for certain!
I decide to do some research on grounds. I wanted to clean all the connectors, bolts, washers, scrape the paint to the ground points and reassemble with Dielectric Grease. I chose to connect all the grounds to a single "Daisy-Chained" path using the Ford Service Manual to locate all the major grounds. With 8 and 4 ga high Silicone Copper stereo power cables, I crimped, soldered and heat shrinked the ends as needed. I started at the PCM ground (near the PCM), then to the PCM Harness shield (at the wiper motor) and wanted to go to the main ground on the block, but couldn't find it. Ford shows it near the engine harness connector, but no luck. For ease of routing/mounting, I chose to go to an open bolt hole on the AC/PS bracket - all with 8 ga. From that same spot, I took 4 ga to the Battery and from the Battery to the Chassis. From there it is 8 ga to the ABS/Horn/Lighting ground behind the Battery.

What about the Ohms to ground now? How about 2 Ohms to all points? Yeah, that's better!
...and the stray AC voltage from the coolant in the radiator to the engine block? <.001 volts. It doesn't get any better...

PCM_Gnd_Before.jpg


PCM starting point...

PCM_Gnd_During.jpg


PCM starting point during...

PCM_Shield_Before.jpg


PCM shield was next...

PCM_Shield_After.jpg


PCM shield finished, with PCM Gnd to the left (dotted lines show path)...

Ends_Before.jpg


All the ground wires were corroded, rusted or worse...

Radiator_Gnd_During.jpg


Radiator Brace and behind Battery...

AC-PS_Mnt_After.jpg


All finished, one ground path start to finish.

Diagram_Gnds.jpg


Here's the layout.
 



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That TSB is what started this. Some other sites suggests that .3v is time to take action as opposed to Ford's .4+v. I decided to go with the lower warning point.
Thanks
 






Further research suggests the main ground is at the starter, or one of the attaching bolts. Going to verify this weekend, and check to see if I can upgrade the power lines to the starter/main fuse box (under hood).

Cooling system flushed with distilled water and Prestone Radiator Flush, results were interesting - rust colored water and some casting sand. I'll know more in the daylight.
 






Coolant.jpg


This is the ST on the Left, the 2005 Focus with almost double the miles, on the right.

Coolant1.jpg


This is the 1st Rinse, still getting some casting sand. Since there was weak green coolant in the radiator and Ford Gold in the reservior, I felt the need to do a 2 rounds with Prestone Super Flush.

Coolant2.jpg


Testing distilled water, the needle doesn't budge.

Coolant3.jpg


From the 1st Flush. Even though the fluid was drained; the system filled with flushing solution and distilled water, there is still plenty of coolant left to register on a coolant tester...

Coolant4.jpg


After that sample, the meter was flushed with distilled water and here are the results of the 2nd Flush. Still plenty of coolant in the mix - don't even think about pouring it in a drain or on the lawn - recylce all fluids drained as you would straight coolant.

Working on the 3rd Rinse with straight distilled water (after 2 flushes). Fluid was clean on the 2nd rinse, but I wanted to be certain the belts, hoses, T-Stat and seal are all leak-free before adding Cooling System Lubricant/Conditioner, 50/50 Coolant and the new Cap. After a couple hundred miles, I'll retest for Electrolysis and post a wrap-up.
 






You realize you're going to cause me a lot of WORK after reading all of this!!!:D:D
 






Yea, I'm like that... :D
Wait until todays thread about flushing the power steering.

After getting quotes of $100-$150 and finding out they were doing little more than just filtering the water and putting it right back in, I thought 10 gallons of distilled water ($8.30) and 2 bottles of flush (@ $7.95 ea) was a bargain. And, as always, I know the work is being done, and done right.
 












Im a little confused, I believe this might be my problem with my truck too, but Im having a hard time following your diagram and then corresponding them to the picture. What is the teal colored line and where is it missing from?
 






Further research suggests the main ground is at the starter, or one of the attaching bolts. Going to verify this weekend, and check to see if I can upgrade the power lines to the starter/main fuse box (under hood).

Cooling system flushed with distilled water and Prestone Radiator Flush, results were interesting - rust colored water and some casting sand. I'll know more in the daylight.
@Fredness
Caught a new post on this, my attention alerted, read it first time. I like your analysis of using resistance readings found between various points, and the fact that you are knowledgeable about electrolysis. That means you probably understand Ph? Solutions having Ph values higher or lower than 7.0 will conduct electricity, the conductivity at 7.0 being very, very low.

So I'm wondering whether you routinely use distilled water in your coolant mix? If so, are you aware that distilled water almost invariably has an acidic Ph, as low as 5.0? That can EAT, man!

All textbooks state "distilled water is pure water having Ph=7.0". That's hype, bullshit. Only way to keep distilled at Ph=7.0 is to distill it under a vacuum, never exposing it to AIR. In practice, distilled ALWAYS gets exposed to air: when you open the container, when you pour it, etc.

Boiler-users know this real well. I hope you do too! If you doubt this, pour a cupful out and stick a strip of Ph test paper in it. imp
 






My head is spinning. BUT I'm all ears so thanks for the write up. Now to find a meter... um....
 






My head is spinning. BUT I'm all ears so thanks for the write up. Now to find a meter... um....
@ptf18

Spinning why? Yer talkin' about Ph and distilled water? It's really simple, but few know it: air contains Carbon Dioxide, CO2, which water loves to suck up, dissolving the gas in it. CO2 breaks up in water to form something called HCO3, which is Carbonic Acid, simply put. Acid eats away metals. For that reason, since engine coolants almost always use water in some amount, the makers of Prestone, etc., add in chemicals which neutralize that acid.

So "Ph" is simply a way of measuring "how acid" is the water, Ph=7.0 being "neutral". Lower than 7.0, it's "acidic", above 7.0 it's "basic".

Your own blood is maintained at all times around 7.1 to 7.2. Yet, lemonade might have Ph=4, REAL acid! Your body automatically adjusts that Ph level constantly. If one's bodily fluids ever go to Ph=4 or so, in ten minutes, yer dead! imp
 






Do you know if the pcm shield wire can be cut? It’s a flat wire and the ring connector is fused to the nut on the stud. Id like to cut it and put a new connector on and find a new ground pole to attach it to
 






Do you know if the pcm shield wire can be cut? It’s a flat wire and the ring connector is fused to the nut on the stud. Id like to cut it and put a new connector on and find a new ground pole to attach it to
@trixareforkidss
I should think so long as you maintain a good, solid ground on the PCM box there shouldn't be a problem. Best have battery disconneced, both batt. cables hooked together electrically when doing any PCM work.
imp
 






@Fredness
Caught a new post on this, my attention alerted, read it first time. I like your analysis of using resistance readings found between various points, and the fact that you are knowledgeable about electrolysis. That means you probably understand Ph? Solutions having Ph values higher or lower than 7.0 will conduct electricity, the conductivity at 7.0 being very, very low.

Absolutely.
And it gets worse every day...
I'm to the point now that I'm debating sourcing "Water, Deionized, ACS Grade, ASTM Type I" ("Lab Water") just out of spite for the industry.
And now that we know plastic capped radiators that only have a life expectancy of 8-10 years, it almost doesn't matter for the daily driver anymore. The Sport Trac recently had an incident with violent overboil (Towing, 100*+, High desert) partially due to an "expired" radiator (passenger side tank seal). I cut open the radiator and STILL found calcium deposits in the lower 1/3 of the radiator.
 






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