Green Tractor Talk banner

1 - 8 of 8 Posts

·
Registered
Joined
·
26 Posts
Discussion Starter #1
So this issue has been brought up a few times here so I thought I'd share my approach to correcting/preventing it.

Backstory: I was mowing along just fine a few days ago and my PTO cut off for no obvious reason. Seat switch and reverse switch have been disabled so that work was immediately suspect. Those checked out so I moved on to the brake switch which was fine. I was generally looking around at the circuit board on the right side (Control/Fuse Module I believe it's called) and discovered that moving the harness caused a red LED to flicker on and off.

Long story short:
PCB_before.jpg

Connectors_before.jpg

Cleaned them with this stuff and a toothbrush:

Cleaner.jpg

After...

after.jpg

And added some of this to the contact surfaces:

Ox-guard.jpg

I did the same to each of the safety switches mentioned above and the two relays below that circuit board. All is well now and I have a bit of confidence that it'll stay that way.


NOTE: DON'T use dielectric compound on contacts!! I've seen a few people say that this is a good idea. Just no!
 

·
Registered
Joined
·
26 Posts
Discussion Starter #2
By the way I cleaned the contacts with the Electronics Cleaner, not the liquid nails in the background.

:laugh:
 

·
Administrator
Joined
·
20,353 Posts
Dielectric grease is great for connectors and the like, but never use it on open relays contacts. The nice thing is I don’t think I’ve seen open relay contacts on a modern tractor in eons. You can use dielectric grease on pretty much every connector without worry of future issues.

Great thread.
 

·
Registered
Joined
·
26 Posts
Discussion Starter #4 (Edited)
Dielectric grease is great for connectors and the like, but never use it on open relays contacts. The nice thing is I don’t think I’ve seen open relay contacts on a modern tractor in eons. You can use dielectric grease on pretty much every connector without worry of future issues.

Great thread.
I'm afraid I have to respectfully disagree. Dielectric is an insulator and is not at all good to have where you want low resistance. I'm aware that it's used this way often and typically without introducing a problem but the stuff in the picture above is a conductor and is meant for this purpose.

Edit: I'm probably being a bit over-zealous about this. Dielectric grease does help prevent corrosion and keeps dirt/moisture out. That's most definitely a good thing. It is an insulator which isn't what you want in a connector but in reality a connector certainly should have metal-to-metal contact so what type of grease is in there shouldn't matter. All that being said, I'd still rather have a conductive grease in my connectors than a dielectric...but I'd rather have dielectric grease than nothing where moisture or dirt is an issue.
 

·
Administrator
Joined
·
20,353 Posts
Conductive grease could be very bad on connectors. When it gets hot it may start to migrate and induce voltage leaks all over. Pin to pin and pin to ground. That’s bad. This is exactly why dielectric grease was brought around. It won’t cause shorts or voltage leaks. You’ll find this recommendation in many many service manuals from many OEMs to include aircraft.
 

·
Administrator
Joined
·
20,353 Posts

·
Registered
Joined
·
1,291 Posts
Conductive grease would be very bad on connectors. When it gets hot it’ll start to migrate and induce voltage leaks all over. Pin to pin and pin to ground. That’s bad. This is exactly why dielectric grease was brought around. It won’t cause shorts or voltage leaks. You’ll find this recommendation in many many service manuals from many OEMs to include aircraft.
I agree with this, I’ve used dielectric grease for years on trailer harnesses to keep them from corroding, it works good and no issues with the connections.
 

·
Super Moderator
Joined
·
5,484 Posts
I learned about dielectric grease at work back in 1993, and that is all I've used for all these years!:thumbup1gif:
 
1 - 8 of 8 Posts
Top