7 pin connector corroded?

Wayne_H · Oct 20, 2011

OK, on every trailer I've owned (two....) pins five and six (left and right turn signal) connector pins on the trailer ALWAYS get corroded, even though they don't get wet. What the heck?

What are the chances the onboard trailer battery is causing some kind of galvanic action to cause the corrosian? As of now I'm disconnecting the 12V battery when the trailer is not in use, this problem comes up once a year....

Is it just me or does anyone else run into this?

Wayne

rkeith · Oct 21, 2011

Probably moisture from the roadway. I used to have that problem but I solved it by using a conductive gel from Advanced Auto and put it on the trailer connection so when I plug it in it puts the gel right where it needs to be! It is conductive so I only put a dab on each of the 7 pins. Seems to work great!

High Compression · Oct 21, 2011

Wayne_H said:
OK, on every trailer I've owned (two....) pins five and six (left and right turn signal) connector pins on the trailer ALWAYS get corroded, even though they don't get wet. What the heck?

What are the chances the onboard trailer battery is causing some kind of galvanic action to cause the corrosian? As of now I'm disconnecting the 12V battery when the trailer is not in use, this problem comes up once a year....

Is it just me or does anyone else run into this?

Wayne

I always have the same problem. Less on the 7 ways, more so on 6 ways. Matter of fact I've converted all 10 of my trailers to 7 ways. A little dielectric grease helps, and what position your plug is stored in, I have found, makes a difference of how much rain gets into it.

Diamondpilot · Oct 21, 2011

Put dielectric grease one then plugs and that will end you problems.

You must clean them up first.

Chris

oldballs · Oct 21, 2011

This is my experience on a 6 (?) pin trailer. Even new it made poor connection. I figured it was corrosion and used a battery terminal wire brush to shine it up. But later I noticed that the connection would always work if the sag in the connection was lifted with a zip tie or cord to hold the line up. A hole in the bumper where the spare tire jack-rod was a handy to place to tie it "up". Cheers. Mike

Wayne_H · Oct 21, 2011

Guys: I have tried the dielectric grease route, I really don't see much difference with that.

But, these connectors have seven pins.... why is there corrosion only on the two pins used for the left and right signal (and brake lights)? That is some kind of clue, the metal does not turn green on its own (at least the other five pins don't...)

Just fishing for ideas, I always keep it dry and it does not get moisture in the connector.

regards

Wayne

Egon · Oct 22, 2011

What do you use to protect from road spray and humidty in the air?

moored4 · Oct 22, 2011

Have you disconnected the plug and then checked it with a ohms meter to see if there is any stray current present? With everything shut off there should not be any current except on the positive battery supply line.

Soundguy · Oct 22, 2011

i pack my connectors with grease unde rthe caps..

soundguy

oldyellr · Oct 23, 2011

Wayne_H said:
Guys: I have tried the dielectric grease route, I really don't see much difference with that.

But, these connectors have seven pins.... why is there corrosion only on the two pins used for the left and right signal (and brake lights)? That is some kind of clue, the metal does not turn green on its own (at least the other five pins don't...)

Just fishing for ideas, I always keep it dry and it does not get moisture in the connector.

regards

Wayne

My guess would be that those two circuits see the highest current and a much higher number of "on" and "off" cycles. If the contact pressure between the male and female terminals is not adequate, it would be just like switch contacts arcing. What I would do is thoroughly clean the terminals inside and out with steel wool and spread the male terminals a bit with a knife blade. This will increase the contact pressure. Then, coat the terminals with dielectric grease to make it easier to insert the plug with the spread terminals and also keep out moisture. What someone else said earlier about supporting the connector also makes sense, because that would reduce vibration "fretting" the terminals.

Maxamillion · Oct 26, 2011

You can spray some WD40 on the contacts. This will help with the corrosion and remove any moisture.

Soundguy · Oct 26, 2011

there is also a porduct you can spray on that leaves a residue to help corrosion, cross conductance and moisture.

deoxit.

oldyellr · Oct 26, 2011

Soundguy said:
there is also a porduct you can spray on that leaves a residue to help corrosion, cross conductance and moisture.

deoxit.

You do mean combat corrosion or eliminate corrosion, I presume.

Yes, I've heard of Deoxit being recommended for restoring low contact resistance in scientific instruments. I also have an old Volvo (a 1992, not really old for a Volvo) and have seen the product mentioned often in Volvo forums because these cars are kept running a long time after "throw away" cars are in the junk yard.

Car Doc · Oct 26, 2011

My camper does it too I just started putting white grease on it and we will see if it helps or not next year. I leave the end hanging down so water cant get in and that doesn't stop it.

I wonder if the house battery has anything to do with it back feeding the power to the plug? elifino :thumbsup:

Soundguy · Oct 26, 2011

oldyellr said:
You do mean combat corrosion or eliminate corrosion, I presume.

Yes, I've heard of Deoxit being recommended for restoring low contact resistance in scientific instruments. I also have an old Volvo (a 1992, not really old for a Volvo) and have seen the product mentioned often in Volvo forums because these cars are kept running a long time after "throw away" cars are in the junk yard.

i work in the electronics industry, and yeah.. that stuff is a lifesaver.

and yes.. understood to be help 'prevent' / 'control' corrosion.

soundguy

davkir · Oct 26, 2011

oldyellr said:
My guess would be that those two circuits see the highest current and a much higher number of "on" and "off" cycles. If the contact pressure between the male and female terminals is not adequate, it would be just like switch contacts arcing. What I would do is thoroughly clean the terminals inside and out with steel wool and spread the male terminals a bit with a knife blade. This will increase the contact pressure. Then, coat the terminals with dielectric grease to make it easier to insert the plug with the spread terminals and also keep out moisture. What someone else said earlier about supporting the connector also makes sense, because that would reduce vibration "fretting" the terminals.

Another factor may be the inrush current. Every time power is applied to the bulb, there is a much higher current flow until the filament heats up and the resistance increases.

bigdad · Oct 26, 2011

Car Doc said:
My camper does it too I just started putting white grease on it and we will see if it helps or not next year. I leave the end hanging down so water cant get in and that doesn't stop it.

I wonder if the house battery has anything to do with it back feeding the power to the plug? elifino :thumbsup:

Be careful using just any grease or oil. I would stay with a non-Oxidizing grease. Like battery terminal grease. Believe it or not, Vasiline.

Soundguy · Oct 27, 2011

most greases these days.. at least premium ones have corrosion inhibitors.

plain old tub axle grease probably don't.. but many of the #2 tube greases do.. at least the ones I use do.. and I want those corrosion inhibitors.

still.. they fact that the petroleum will 'dewater' the plug.. that in and of itself helps.. no water.. or air, due to the lube coating, then less chance of corrosion.

soundguy