My 02 F350 7.3 developes considerable corrosion on all the battery positive side connections. Battery terminals themselves, alternator cable, starter cable, junction block going to main central junction block, etc. Ground connections get "dirty" as usual but nowhere near as bad as the positive side which grows green corrosion even though cleaned then treated with dialectric and white grease. I searched through the SD and 7.3 forums but can't find a reasonable explaination of why it happens or how to prevent it other than to preform considerable timely maintenance every week or so to stay ahead of it. Any ideas or help?

 

Those little felt thingys work well.

http://www.ebay.com/itm/like/251467929988?lpid=82

 

Your going to want to check the cables for damage under the insulation.
The easiest way and best way is to do a voltage drop test.
The reason for the corrosion is leakage from the post seals or the vent caps.
It does not take much acid to mess up a cable.

Jmatthews is correct about the felt washers they do help.

Here is a Youtube on the voltage drop test. You need to check
both cables and the grounds. If the cables are growing fuzz
then they most likely have corrosion under the insulation. That
will cause problems with charging the battery and getting enough
current to the starter when you start it. The key to remember is
0.5 of a volt and there is a fault and most likely the cable is bad.


Sean

 

Some have said that certain cable brands and clamps are prone to dissimilar metal type corrosion. Have also heard claims that Exide batteries are especially prone to corrosion on account of their construction.

Sent from my iPhone using IB AutoGroup

 

if you use a trickle charger in and enclosed area the battery gases will localize and cause corrosion.

 

I do use the felt washers. OEM Ford cables. Motorcraft batteries. Trickle charge when needed (very rarely until now). But it is not just at the battery, all the cables that carry high current are corroding. I will try the voltage drop tests but looks like I need to completely rewire the charging circuit, the starting circuit, and the main circuit through the firewall to eliminate all the corrosion that must be migrating through the insulation. I was hoping that there was some other solution to prevent future corrosion. I will liquid tape seal all cable ends as I replace them to try and prevent future events. Thanks for the help so far. I'll try and update as I go.

 

The amount of corrosion that you describe is a little unusual. You might want to check to see if the output on your alternator is high (bad voltage regulator) causing the battery to overcharge and generating above normal gassing and corrosion. You could also test the batteries to see if they are operating normally.

 

One thing to look at, the XLT Ranger got some attention lately after a couple weeks tuning up the 64 F100. Ranger has a ground strap at the block, the firewall, and I bet one to the frame, just like my 64. Figured it wouldn't hurt to clean them up for good electrical contact. Always clean and treat connections before corrosion is visible.

Where is the strap on the block anyway. sure is a lot of hoses stuffed in that engine bay. Well found it, and it looked like a chemistry experiment. Tough to reach but undid the main grounding strap from block w/ a 13 Mm socket and extension ratchet, and found they use it seems an aluminum bolt to secure a ground plate to the block.

Aluminum tends to loosen over time with heat/cool cycling and bolt was not particularly tight at all. I bet the 150s have the same type?? Dunno. Tried to get a file on the block pad, used some NO-OX, the whole thing gets corroded pretty bad and is worse at 5 years than anything I've seen.

This is a problem because that connection is just as important as the battery side but isn't visible so much like battery clamps, and it's a pita to get to. I don't know what half the components are by name attached to the engine, but know for sure loose corroded grounds will screw things up real good. The truck itself is remarkably rust free, one of the reasons I bought it. Has 25k on it now.

On my F100 it's smooth sailing access wise, even chased the threads out on the block ground pad and filed the flat free of paint, grime down to bare metal. Star washers are supposed to be used on grounds. The 09s ground point was just plain rust!. Got it cleaned up pretty good, but gonna go at it again, cleaning this up (just like battery terminals) will pay for itself. It seems like the aluma-steel-whatever mix of materials they used as the main ground point doesn't get along well together. A copper bolt wouldn't hurt here maybe, but that costs another .60c. Hm.

 

hm. that's just strange. usually caused by dissimilar metals
squabbling.

a shot in the dark.... are the cables copper clad aluminum, or copper?
you can tell by the weight....

there is a number of products that you can experiment with,
but there is this company that makes some pretty amazing
stuff....

http://www.armitelabs.com/products/C...nti-Seize.html

there are a lot of companies making "copper based" anti sieze
products, but this one is conductive, so don't smear it anywhere
you don't want the electricity to go.

this is not a 3-n-1 kinda company. they make stuff on steroids.

use sparingly.