Trailer not accepting charge from tow vehicle

rkj__

On my most recent trip with the T@b, I discovered the trailer battery was not being charged by the tow vehicle. 

I bought a mutimeter. When I check the truck side of things, there is power to the 12V battery pin. 

If if I touch the probes of the multimeter to the trailer plug pin connections, I get nothing. 

The trailer is a 2016 CS-S, with no Jensen.  There is no battery disconnect switch in the trailer.

Im not great at dealing with electrical issues.

Help? 

mgreen2

where are you testing the trailer plug connection?

rkj__

mgreen2 said:

where are you testing the trailer plug connection?

The plug at the end of the cord, which plugs into the tow vehicle.  One probe on the ground pin, one probe on the 12V / battery pin. 

RollingBnB

If you don't have a battery disconnect do you have the auto reset circuit breaker? They go bad. It should be inline with the positive wire off the battery.

rkj__

RollingBnB said:

If you don't have a battery disconnect do you have the auto reset circuit breaker? They go bad. It should be inline with the positive wire off the battery.

Coming off the battery, I’m pretty sure it’s just a fuse. 

If if there was a problem in the main positive line off the battery though, that would mean nothing would work off the battery, right?  The battery is running all the 12V circuits in the trailer without issue. 

RollingBnB

rkj__ said:

Coming off the battery, I’m pretty sure it’s just a fuse. 

If if there was a problem in the main positive line off the battery though, that would mean nothing would work off the battery, right?  The battery is running all the 12V circuits in the trailer without issue. 

Ah, ok. Can you follow the 7 pin cable back to the junction box under the trailer. All the wires connect in side it. Maybe the wire came apart.

Sharon_is_SAM

If the pins are intact and not dirty/corroded, I would also check the junction box.  You probably know this, but, disconnect your battery/shorepower before tinkering inside the box.

rkj__

Ok, I'll inspect the junction box for anything that is visibly wrong, and report back.

Michigan_Mike

rkj__ said:

If if I touch the probes of the multimeter to the trailer plug pin connections, I get nothing. 

The trailer is a 2016 CS-S, with no Jensen.  There is no battery disconnect switch in the trailer.

So you have verified the following:

The fuse at the battery is intact and not blown?

Connections at the battery are clean, not corroded, lugs are tightened down good, wire connections are crimped tightly, not loose, etc?

Positive & ground wire connections at the battery are intact and making good electrical connections?

I'm not sure when the factory started installing the on/off battery disconnect switches in the trailers but if there is one it should be in the tub area I'm guessing.   

rkj__

Michigan_Mike said:

rkj__ said:

If if I touch the probes of the multimeter to the trailer plug pin connections, I get nothing. 

The trailer is a 2016 CS-S, with no Jensen.  There is no battery disconnect switch in the trailer.

So you have verified the following:

The fuse at the battery is intact and not blown?

Connections at the battery are clean, not corroded, lugs are tightened down good, wire connections are crimped tightly, not loose, etc?

Positive & ground wire connections at the battery are intact and making good electrical connections?

I'm not sure when the factory started installing the on/off battery disconnect switches in the trailers but if there is one it should be in the tub area I'm guessing.   

Fuse ok - all 12V features run on battery power ok.

Leads screwed to the battery are tight, and free of significant corrosion. 

I have not inspected every crimp connection.  I'll look for any issues there. 

I believe the cutoff switches were added late 2016 / early 2017.  As mentioned, my trailer does not have one. 

Verna

If you do not have an AGM battery, are the fluid levels in the battery at an acceptable level?   I know, that was probably the first thing you checked. 

rkj__

Verna said:

If you do not have an AGM battery, are the fluid levels in the battery at an acceptable level?   I know, that was probably the first thing you checked. 

It's a flooded battery.  I checked it recently, and found the water level basically unchanged.  It does not tend to lose significant amounts of water.

There are no issues charging off of shore power. 

ChrisandAlexis

@rkj__ , with battery disconnected check continuity between junction box and pin on end of plug that goes to TV. Possibly open in cable between junction box to the plug that goes into TV.

rkj__

Thanks.  I found this image posted by ScottG.  It looks like it's the terminal second from the right that is of interest to me.  And, it's the heavier gauge black wire, with the yellow connector I should check for continuity, correct?

I'll try to check it out sometime this week.

RollingBnB

That should work, and the post to the right looks like neutral. Check that to.

rkj__

Ok I looked at this tonight. 

I opened the the junction box. Saw nothing weird, except that a white wire was pinched by the screw on cover. The casing was squished, but not cut. The positive and ground posts had power. Both the ground and 12V wire tested good for continuity. 

So, if the truck end was good, and the trailer end was good, the only thing left was the connection between the two. 

I took a small nail file to all the pins to clean them up. 

I plugged in the running truck, and low and behold, I saw a voltage rise on the trailer. 

I went and re-checked the 12V and ground line on the trailer plug, and got a reading, unlike the last time that checked. That part I found a little odd, but again, maybe it was just dirty pins that messed up the test. 

So, for now it seems to be working again. 

I’ll continue to monitor the situation. 

MuttonChops

rkj__ said:

. . .  file to all the pins to clean them up.

Might add one of these to your tool kit:

jkjenn

I also use a little dielectric grease to help keep the 7 pin corrosion-free.

ericnliz

X2 @jkjenn! I use it all the time. I also use it for my shore power cord on both the trailer end & the cord itself.

Verna

@rkj__ when I unhitch, I make a conscious effort to make sure the end of the T@B side of the 7pin connnnector is pointing down, to help try to keep it dry. That helps, but sometimes, the connection will need to be cleaned. See the suggestions above for anti-corrosives to keep on hand. 

ericnliz

@Verna, I try to keep mine downward as well. The dielectric grease helps keep the moisture out of the pin slots. A good visual once in a while never hurts though.