Tailights Inop when hooked to TM

[Pagosa]

When I have my F150 electrically connected to the TM I have power to signals,turn signals, brake lights but I have no tail lights. Any suggestions or past experience on what might be the problem. Trailer or Truck?

Thanks for the input
Pagosa

[rvcycleguy]

Should be a dual filament bulb. Half the bulb is stop lights and half is running lights or as you say tail lights. Check the bulbs. Hard to suggest that both are out at the same time though. You might check the 7 way plug for debris, corrosion on one of the terminals or bent terminal not connecting inside the plug harness.

[Pagosa]

I forgot to mention that none of the side marker lights are working either. I will check the pins.
Thanks
Pagosa

[rumbleweed]

Not sure about your 150, but my Silverado, has a separate separate set of fuses for the trailer lights. Check the plug on the truck to insure the signal is at the connector.

[Barb&Tim]

Have you checked all your fuses in your TV? If so and they are all ok then a check at your TV bargman connector for the presence of 12v on pin (#3 Green -- tail/running lights) should be next.

Tim

[Redhawk]

What Bob said...get a pin out drawing and a DVM, check the signal on the truck connector first, then start following it back. Check your trailer ground wires carefully if all is good on the connector.

[scrubjaysnest]

If you don't find anything as mentioned above, check the intermediate connections in the lower refrig compartment. TM used bullet connectors on ours and they were the wrong size for the wire. This resulted in bad connections.

[Bill]

I agree that the first step is to check the voltages at the back of the tow vehicle. There is a pinout diagram in this album

http://www.trailmanorowners.com/forum/album.php?albumid=8

Bill

[Redhawk]

Did it ever work on the F150?

[Pagosa]

At this point I have power coming from all pins on the truck. Not sure if Im doing the right checkout on the trailer but I used a ohm meter on the pins on the trailer receptacle and all of the pins returned a reading except the #3 pin. Im assuming I have a open circuit on #3 pin for the running lights. Im not an electrician so any suggestions?
Pagosa

[Barb&Tim]

At this point I have power coming from all pins on the truck. Not sure if Im doing the right checkout on the trailer but I used a ohm meter on the pins on the trailer receptacle and all of the pins returned a reading except the #3 pin. Im assuming I have a open circuit on #3 pin for the running lights. Im not an electrician so any suggestions?
Pagosa

Note: See Bill's post #14(below) where he explains when and where you should see voltage readings on your TV bargman connector.

I assume you are using a multi-meter which allows you to check for:

Voltage in (Volts)
Current in (Amps/miliamps)
Resistance in (ohms)

But for the problem you are having to determine whether it's the TV or the TM,
You should be checking for DC voltage +12v on pin 3 with the voltage setting on your meter. If it has a range setting, set it higher than 12v.

Connect meter red lead to pin 3, meter black lead to ground.


***By the way, using an ohms setting to check for voltages can possibly (EDit:damage your ohmmeter).(your right Bill :) ) You should only use the ohms setting when you know there is no voltages present and you are checking for continuity.

Tim

[Pagosa]

Thanks for the reply I will check as you suggest tomorrow.

[Barb&Tim]

Pagosa. Still wondering if you have ever had these running lights working before or not?

Tim

[Bill]

Let's clarify. All of the pins except Ground should show 12 VDC when the associated switch in the tow vehicle is turned on. In other words, the pin for the backup lights should show power if the ignition is on and you put the transmission in reverse. The pins for the left and right brake / directional lights should have power if you press the brake pedal. The running (marker) lights should have power if you turn on the headlights. The brake pin should be energized if the ignition is on and someone is stepping on the brake - however, since the vehicle is not moving, the reading on this one may be wonky, depending on your brake controller. And of course the 12 VDC battery charge line should show power as long as the ignition is on (many cars) or all the time (other cars).

If none of these functions are activated (no one is stepping on the brake, for example), then the only pin that should show 12 VDC power is (maybe) the battery charge line. Is this what you are seeing?

As for using an ohmmeter on the trailer half of the the connector? You should check only the lines to the brakes and the lights. In each case, you should expect a reading of a few ohms, say in the range 2 to 10 ohms. If you try to measure the 12 VDC battery line with an ohmmeter, you will get a meaningless reading at best, and destroy your multimeter at worst. I don't think you risk blowing any TM fuses, though.

Tim's question - did the lights ever work with this vehicle? - is a good one. The answer will steer the troubleshooting steps.

Bill

[rumbleweed]

If one or two of the lights don`t work, it could be the bulb,socket, or ground wire to the TM skin. If none of the running lights work but some lights work it is most likely between the plug and and the first connection point for that line.

[Pagosa]

Using a test light on the TV connector all pins light up the tester. All lights on the trailer function except the taillights and marker lights. Are the marker lights and running lights in a series setup? All the lights have functioned in the past until I hooked up to the TM the last time. It had been a couple of months since I had taken the TM out camping.
I was trying to use a ohm meter on the trailer connector to see if I had a open circuit on the 3 pin to the running lights and it didn't return a reading at all. I know my ability electrically is handicapping me on this issue. It may be time to head for the RV dealer. Thanks for all the help

Pagosa

[Barb&Tim]

They are in a parallel setup, 12v is applied to each bulb.


You might try scrubjaysnest's suggestion in post #7 above.

[Pagosa]

That is a possibility. I will check it out.
Thanks

[rumbleweed]

check behind fridge ( lower outside access vent) you might have a lose connection where the cable breaks out to the various lights. Some TMs use wire nuts and some use terminal strips or crimp connectors

[CAmark]

I had a similar "untrace-able" problem with my TM's left brake/turn light and finally traced it to a spotty connection between the two Bargman halves. When "plugged in with some muscle behind it" the light worked to get me home...dismantling and re-seating the TV plug made this a much more reliable connection. A thought from a mechanical guy -- could you use a jumper wire between the two plug halves to diagnose if this is causing Pagosa's problem?

Mark

[Bill]

Mark -

You remind me that I have experienced the same problem at the Bargman. The pair of springy metal blades in each of the socket cavities gradually bend outward and separate, leaving a too-wide gap between them. Result - the connection fails. I simply slipped a screwdriver behind each springy blade, and bent it inward toward its mate, to close the gap. Simple, but it worked!

Bill

[rumbleweed]

The contacts also oxidize over time and get dirt on them. You can use a small nail file to gently clean up the surface for a better connection.

[Kwantau]

I coat both female and male end brass contacts of the Bargman with a dielectric grease once a year and never had any corosion problems. Also aids in sliding the Bargman plugs together.