Maintenance & Restoration

Khristy G · 05-11-2014, 06:49 PM

We just put on an adjustable hitch, 7 pin was already hooked up to truck, trailer battery connected, as soon as we lowered trailer on to hitch sparks occurred, fuse finally blew at battery, when battery not connected no sparks. We did not have this issue when we had just a 2.5" drop hitch. Help please. Thank you.

Bob Miller · 05-11-2014, 07:14 PM

Something is missing in this story

As soon as the 7 pin plug was connected there should have already been a ground bond between the two vehicles so any connection caused by the hitch should have been redundant.

By chance did the draw bar on the new hitch get tangled in the wires behind the hitch?

Sounds more to me as if someone has been fixing things somewhere alone the line and that isn't included in the story.

I'd suggest starting with the 7 pin plug connectors and be sure it's not shorted inside the connector, then go on to the other wires.

Short of an Alien intervention, there's nothing I know of that will cause that problem

Carol H · 05-11-2014, 07:17 PM

Hope someone with more electrical no how jumps in Khristy but first off I would suggest it has nothing to do with the changing of the ball more likely a 12v electrical short happening.

I am assuming that you plugged the trailer into the tug before you put the trailer down on the ball? Where the trailers running lights or anything else on at the time? Is your wiring harness in good condition or are there any bare wires showing or touching the frame of the trailer? Hows the ground on the trailer?

Edit to note: Bob also raises another possible issue - wires on the tug side touching the new ball mount?

cpaharley2008 · 05-11-2014, 07:52 PM

The plug should be the last thing you hook up.

Bob Miller · 05-11-2014, 07:59 PM

Electrically speaking, why should it make any difference if the 7 pin plug is connected before or after the coupler?

Bob Miller · 05-11-2014, 08:01 PM

I didn't ask earlier, and am not sure how it could make a difference, but was the 120 Volt shore line still connected when all this happened?

Khristy G · 05-11-2014, 08:04 PM

Something is missing in this story
The 19seventy8 trailer is new to us. Either we didn't notice the sparking before or something changed. We've only towed it home and then parked it in the backyard and started cleaning it up! The PO definitely did some home wiring.

The trailer battery is located on the rear bumper. Positive and Negative run into the nook below the furnace and then into the OE converter. The positive connects to the black power wire from the loom before the converter. The negative connects into a group of wires. There is no ground to the frame anywhere that I've seen. The group of wires under the driver side of the gaucho look pretty unmolested relative to the photos I've seen here. There's a 20 amp fuse on the black wire, a smaller fuse on the frig black wire, and two groups of grounds in a galvanized junction box.

The PO did add a small fan and a small dvd/tv player into the light circuit.

It all seems to work fine if the tow vehicle is not connected via the seven pin connector.

I grounded the battery to the frame and instantly blew the fuse on the positive lead at the battery.

The seven pin on the trailer looks fine to me if a little corroded and may have been dragged once as the metal casing is ground flat but does not appear compromised. And the TV is a honda with 5000 miles and a factory tow package.

By chance did the draw bar on the new hitch get tangled in the wires behind the hitch?
No chance ... the honda factory wiring is very clean

I'd suggest starting with the 7 pin plug connectors and be sure it's not shorted inside the connector, then go on to the other wires.

I am assuming that you plugged the trailer into the tug before you put the trailer down on the ball?
We've tried many combinations!!!
If the seven pin from the trailer is connected to Honda there is arcing at the hitch.

Where the trailers running lights or anything else on at the time?
No

Is your wiring harness in good condition or are there any bare wires showing or touching the frame of the trailer?
Wire harness from seven pin on trailer to area beneath gaucho all looks very good. Seems like it has something to do with the ground wire via the tow vehicle??

Hows the ground on the trailer?
There does not seem to be any ground to the frame of the trailer.

The PO did not have any fuse / circuit breaker protection near the trailer battery. I added that as I thought the wires looked too tight to the battery so while I was in there... so it seems possible it was arcing and he didn't know it? That said the I haven't seen any wires that look burnt.

The first day we had it home I know I checked the voltage at the battery while the Honda was running and I saw 13.6 V so I was happy. I'm pretty sure that was after I put the fuses in... but the arcing we've seen today does not always blow the fuse but I'm quick to disconnect the battery.

I'm going to check voltage from black to white on the trailer plug with the converter on "batt" and we'll see what that shows. Not exactly sure how to to check for internal shorts in the connector...but I'll think about it!

Thanks so much!!

Khristy

Khristy G · 05-11-2014, 08:05 PM

Bob, no shore power involved. Thanks, K

Carol H · 05-11-2014, 08:14 PM

Quote:

Originally Posted by Bob Miller

Electrically speaking, why should it make any difference if the 7 pin plug is connected before or after the coupler?

I can't say for sure but I would think that it could make a difference if the trailer is actually using the vehicle as a ground due to it not itself having its own ground.

Khristy G · 05-11-2014, 08:19 PM

I get battery voltage (12.5 volts) when the positive side of the meter is on the positive terminal of the seven pin connector and the negative side of the meter is on any of the other terminals except the center terminal (which I saw is disconnected under the gaucho.

Thanks!!

Bob Miller · 05-11-2014, 08:31 PM

It you are reading ground through the other pins you are either reading through a light bulb or a short. You need to find out which is the case. Easiest way is to get the standard plug diagram and remove the tail/stop and running light bulbs to rule out a short.

When I get a new-to-me FGRV I usually just start over with the wiring and erase all of the previous owner(s) boo-boos, it is usually quicker and much more reliable.

And, BTW, you need a frame ground, if just to rule out existing short circuits.

Lynn Musgrave · 05-11-2014, 08:41 PM

Had DH read this tread...he liked all the suggestions,but did ask if you had checked everything with a Volt Meter? to see if the wiring in the TV and trailer was wired right

Byron Kinnaman · 05-11-2014, 09:34 PM

This appears to more than a simple problem. I would suggest the package be taken to somebody that knows trailer wiring and have them find the problem. 12 volt systems are often more prone to cause fires than you might think.

Khristy G · 05-11-2014, 09:41 PM

Bob,

Thanks. All my bulbs are good so it sounds like I need to pull some bulbs and see what happens.

I did add a frame ground from the negative terminal of the battery out of curiosity this afternoon and when I hooked up the battery I instantly blew the positive fuse I installed at the trailer battery. So:
1) no trailer battery, no sparking with seven pin connected
2) trailer battery in system, no sparking with seven pin disconnected (i.e. trailer hitch to Tug hitch ball does not seem to make the ground connection)
3) trailer battery connected, seven pin connected, sparking at hitch and blowing fuses at battery (20 amp fuse on black wire under gaucho unscathed so far)

I've got a blue sea fuse box coming tomorrow so that will get me going on a re-wire. But now I'm not so sure I understand what's going on!!

I was thinking I'd put the fuse box under the gaucho. Run (a new) hot wire from the battery, the black wire from the Tug, and the black wire to the converter on the positive stud of the box. I will also put a 20 amp fuse or auto circuit breaker on the black wire from the tug to the positive stud.

The Fridge positive and negative would get wired through the fuse block. A new inline water pump will get added to the fuse block.

I'm a little less clear on the negative side. I was thinking I'd have the ground from the tug, ground from the trailer battery, and ground to converter on the negative stud of the fuse box. I'd use three of the negative bus locations for the brake, turn signals, and running lights. Should I ground this to the frame as well as grounding the battery to the frame? That's what I was planning to do but too much FGRV reading has me very confused on the frame as a ground.

Thanks for all the help!! I'll continue to report in!

Khristy

Khristy G · 05-11-2014, 09:46 PM

Byron, I hope you're wrong

... but I appreciate the realistic advice! It seems like a pretty simple system though the converter and the grounding seems more complicated than my old camper van.

-K

frankcfx · 05-12-2014, 01:17 AM

If it didn't spark with the 2.5 drop hitch try it again with the 2.5 drop hitch.

Borrego Dave · 05-12-2014, 02:56 AM

A different hitch lift size wouldn't make any difference to the wiring unless going from one to the other put the connector wire in a short coupled situation and maybe caused a short in the line that shorted out. You may want to also look at your tugs plug connections before you go into the trailer for the problem. Always ground from the tug to the trailer, not through the ball. The company I retired from had 150 vehicles and 95 % of any electrical trailer problems was a ground problem. Good luck to you.

Raz · 05-12-2014, 05:53 AM

Does your trailer have electric brakes? That's one circuit that is more likely to have a connection to the frame, intentional or otherwise. That said, bear in mind that every poor wiring job was done by someone who thought they knew what they were doing. Faults like this are difficult to find and can be dangerous. Consider getting some one knowledgable to help. Raz

Bob Miller · 05-12-2014, 08:32 AM

Everything 12 volts should be grounded to the frame simply because that's where the battery(s) are (supposed to be) grounded.

A different grounding question comes up if you are using a Inverter (12VDC to 120 VAC) about grounding it, but that wasn't mentioned earlier.

Also verify that your shore power cord is correctly connected. Easiest way to do this is to always have an outlet polarity checker on hand (<$10 at hardware stores)

BTW: If you still have the original, now 35 y.o., converter, it might be time for that to go as well..... a p.o. may have redone wiring to compensate for a short or ac leakage in that piece of antiquity.