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BarneyS's avatar
BarneyS
Explorer III
Jul 10, 2022

Cleaning trailer electric cord contacts

Member RoyF posted the following in the 5th wheel forum and I though a lot of you might like it also. I asked and received his permission to post it again here.
My italics and red print.

I finally found the little wire brush that is small enough to get between and clean each of seven sections of a trailer's seven-pin connector, so I pass this discovery along in case I am not the only one who did not know how to find them.

It's called a air-gun brush, or a paint-sprayer brush. I found some at Harbor Freight, but in the paint-sprayer department. (Thanks to Harbor Freight for directing me to the right department.) Amazon has them, too.



A little later I posted a link to where the brushes could be purchased.
Is this the one?
Air brush cleaning tools
Barney

He responded:

Thanks, BarneyS, you have it.

I had been getting "trailer disconnected" and "turn signal not working" messages off and on for some time, and my trailer brake and turn lights finally stopped working. I was afraid that the problem might be hard to trace, but just cleaning the trailer's 7-pin contacts solved the problem.

The OP

  • I bought the brushes yesterday and will try them out. TY
  • Thanks for the info. RoyF is fortunate that cleaning his 7-pin connector worked. We got the "trainer disconnected" message and it was the actual trailer brake wires.
  • Mechanical cleaning is sometimes needed, but there are electrical contact cleaners in a spray that work great. One brand available through electrical supply and pro audio stores is De-Oxit brand, works great on analog mixers, and the amount of electrical flow is critical there.
  • As I was hooking up to leave (on 7/4) for a 6 week trip into Canada, I got the "left turn signal failure" message. I sprayed carburetor cleaner into each of the 7-pin's sockets and scraped it with a small screwdriver. I followed that with WD-40 and the screwdriver. Fixed the problem so far (10 days later). Carburetor cleaner and WD-40 were what I had on hand and I was getting ready to pull out.
  • Thanks to Roy and Barney for this post -- I found it in the archives, and it was very helpful!
  • Just be careful with the tiny brushes, if any of the metal bristles break off and lodge between the contacts, you might wonder why fuses are blowing.
  • We went on a 6 week RV caravan touring the Canadian Maritime provinces, leaving home on July 4th. The morning we were pulling out of the driveway to start the trip, the truck said the trailer's left turn signal was not working. It wasn't. I have a tester that said the truck was supplying current, so I turned my attention to the trailer's 7 pin connector. I filled each contact with carburetor cleaner and used a VERY small flat blade screwdriver to work it into the contacts. I shook that out and filled each contact with WD-40. Did the same trick with the screw driver. I shook it out and plugged it back in. Eight weeks later, and I haven't have a recurrence.
  • Bobbo wrote:
    As I was hooking up to leave (on 7/4) for a 6 week trip into Canada, I got the "left turn signal failure" message. I sprayed carburetor cleaner into each of the 7-pin's sockets and scraped it with a small screwdriver. I followed that with WD-40 and the screwdriver. Fixed the problem so far (10 days later). Carburetor cleaner and WD-40 were what I had on hand and I was getting ready to pull out.


    The WD-40 will accumulate over time. DAMHIK

    I'd use de oxit D 100.
  • deoxit for cleaning is great.

    I also use dielectric grease, which should prevent any oxidation, but has the bonus of preventing arcing.

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