RVing Drives Me Nuts ---- Electrical Issue

[Hoppypoppy]

Brought my 2002 Cardinal home from storage last Fri. Checked lights - everything fine. 5er sat in front of my home til this morning. (Tues) Hooked it up, ready to go, no tail, brake or turn signal lights on right side only. Left side fine. First thought was a ground issue. Now the dumb question.....is the only ground on these rigs the ground included in the power plug to tow vehicle? Any other suggestions? Thanks all.

[wa8yxm]

Generally the ground wire in the plug goes to the frame.. Then ground leads on the assorted other things also go to the frame.. It is possible for the light socket to have a bad ground.

That said, Some folks the ground lead runs all the way to the lights.. On my car, when I'm towing, the tow lights are 100% independent from the rest of the ride. They only ground via the motor home.. and a dang poor job of it they did too (till I fixed it).

[Hoppypoppy]

jmckelvy wrote:

Hoppypoppy wrote:
Please forgive my ignorance, but I am an electrical illiterate. I went back to the 5er and tried all the suggestions I had received at that point. More came in later, and I hope to go back again today. (little under the weather) My latest question.....is it possible, the ground wire in the power cord is itself grounded to the pin box itself? This may be the ultimate in stupid questions, but I want to eliminate all possibilities before I tear into the light fixture itself. One of the problems I am having in locating a ground wire is, the trlr is an All Season so no access from underneath. Thanks again for your help and patience.

The three posts prior to yours are the most accurate. This problem is not related to your 7-pin connector given the symptoms you report. It appears you have a single bulb system. The only things common to the tail, brake and turn lights are the bulb itself, the socket with the ground (common) connection and the ground wire to wherever it connects to the ground for the rest of the lights that do work.

Start by removing the bulb and ensure a good clean connection to the socket. Make sure you have a good bulb. Let us know what you find.

Again pardon my dumbness....when you say a "single bulb system" are you saying one of the three bulbs could be out, and that is taking down the whole trio of lights?

[time2roll]

Hoppypoppy wrote:
My latest question.....is it possible, the ground wire in the power cord is itself grounded to the pin box itself?

Yes that is possible. Easy to check continuity from the 7-pin ground terminal to frame. Does not matter where it connects just so that it does.

[jmckelvy]

Hoppypoppy wrote:
Please forgive my ignorance, but I am an electrical illiterate. I went back to the 5er and tried all the suggestions I had received at that point. More came in later, and I hope to go back again today. (little under the weather) My latest question.....is it possible, the ground wire in the power cord is itself grounded to the pin box itself? This may be the ultimate in stupid questions, but I want to eliminate all possibilities before I tear into the light fixture itself. One of the problems I am having in locating a ground wire is, the trlr is an All Season so no access from underneath. Thanks again for your help and patience.

The three posts prior to yours are the most accurate. This problem is not related to your 7-pin connector given the symptoms you report. It appears you have a single bulb system. The only things common to the tail, brake and turn lights are the bulb itself, the socket with the ground (common) connection and the ground wire to wherever it connects to the ground for the rest of the lights that do work.

Start by removing the bulb and ensure a good clean connection to the socket. Make sure you have a good bulb. Let us know what you find.

[Hoppypoppy]

Please forgive my ignorance, but I am an electrical illiterate. I went back to the 5er and tried all the suggestions I had received at that point. More came in later, and I hope to go back again today. (little under the weather) My latest question.....is it possible, the ground wire in the power cord is itself grounded to the pin box itself? This may be the ultimate in stupid questions, but I want to eliminate all possibilities before I tear into the light fixture itself. One of the problems I am having in locating a ground wire is, the trlr is an All Season so no access from underneath. Thanks again for your help and patience.

[Bobbo]

Hoppypoppy wrote:
Brought my 2002 Cardinal home from storage last Fri. Checked lights - everything fine. 5er sat in front of my home til this morning. (Tues) Hooked it up, ready to go, no tail, brake or turn signal lights on right side only. Left side fine. First thought was a ground issue. Now the dumb question.....is the only ground on these rigs the ground included in the power plug to tow vehicle? Any other suggestions? Thanks all.

The 7 pin does not have a "right side" pin and a "left side" pin. Neither does it have a "right side" ground or a "left side" ground. If the problem was in the 7 pin, it would not just affect one side.

While the brake light and turn signal are one circuit, the tail light is a separate circuit/filament. If it was a hot wire, only the tail light, or, only the brake light/turn signal would not be working. It is unlikely that both the hot wires would fail at exactly the same time. (Unless a critter got in there and chewed them.)

The evidence (2 separate circuits, with one of them only affected on one side) points to a bad ground on the light fixture. Try running a temporary separate ground wire from the light fixture to a known good ground. I'll bet that solves the problem. If so, you can attach a permanent ground wire from the light fixture to ground.

If the ground between the 5er and the tow vehicle was the problem, it would not be only that one light fixture.

[jrnymn7]

If it's the 7 pin plug itself, why would half of pin 3 be working?

[mobilefleet]

betcha it's just the bulb. Remove lens and either reseat the bulb or replace it. Prob not making good contact

[YC_1]

Drop one of the lights in question, Or if you can just open the lens and pop a bulb out do that. Use a cheap 12 volt test light to see if it lights when contacting the connectors at the bottom of the socket. If it does, drop the whole fixture out if you already have not. Now put the bulb back in and check the wire in and wire out with the test light. If it lights up on both wires you have a bad ground. Install a new ground wire or find where yours is not making contact anymore.

[time2roll]

Yes power up the 7-pin and look for a bad ground.

Might be easier at twilight or evening to visualize bulb brightness also. Sometimes with a bad ground it will back feed through a dual filament to some other ground connection that is working.

[MrWizard]

Lights are on the tail end of circuit
Lights are grounded
Power comes from the seven pin connection
You have..either lost connection on the seven pin for the right side
Or
Lost the ground for the right side of the tt, done where in the tt

Start with the seven pin, turn on lights look for power into truck side and out to tt Side of seven pin
Work down the tt Wiring from that point

[Hoppypoppy]

Thanks folks. Hope to head back over to the 5er this a/noon to try these suggestions. If you step outside and hear a grown man crying, you'll know I couldn't isolate the problem.

[RoyB]

When this happens to me I just squirt some WD40 into the connector and move it around three or four times. The trailer safety lights all usually work after that... My 7-way connector has a bump on it that acts as a safety latch.

Always carry WD40 and Duct Tape in my RV tool box...

When you start tearing things down to test things you may create more of a problem that wasn't there before.

Do the easy things first...

To answer your ground question on my trailer the ground wire always follows the wiring to each of the DOT Safety lights. Very few places on my trailer actually use frame ground as a connection point. A BLACK HOT +12VDC wire and a WHITE GND -12VDC wire goes to all of the 12VDC items in both the DOT safety lights wiring and the trailer 12VDC Distribution Panel where the fuses are located...

The older trailers may have only used a +12VDC hot wire and FRAME GROUND connection for the 12VDC return to the battery.

Roy Ken

[Dr_Quick]

I would suspect a bad ground to the right side of the trailer. Some lights ground to the frame and some use a separate wire all the way thought.

Try this, take off both of the back taillight lenses and run a jumper wire from left side ground to right side ground and see what happens. This would be the outside metal art of the bulb socket, it you have the metal base bulbs with the prongs on the sides. If not you could go from the "Green wire" I believe which is the ground between the sockets. If that fixes it you know it is the ground.

Light ground wires are "looped" from light to light starting at the front of trailer usually. Then just look for most convent spot to add a ground wire to circuit.

Also in junction box for Pig Tail, could also be a loose ground wire to right side of trailer.

[midnightsadie]

spray the plugs with contact cleaner . before taking things a apart.