Tow vehicle electrcal hookup

[RandandDoug]

I am having a problem with the trailer electrical plug on my 2006 mountain aire 4304. I thought it was a bad pigtail I used when hauling the jeep. Replaced the plug, couldn't get it to work properly, thought I was doing something wrong. But now I've hooked up our enclosed trailer and it won't work right either. I get trlr marker lights, and the brake controller seems to work fine, but no trlr tail lights, no turn signal or brake lights.
I have found a fuse box at the rear of the coach, but the fuses are unmarked. Question is has anybody had the plug receptacle ever go bad on them. Doesn't seem like I can ever remember hearing anyone say one wore out or caused a problem. Wondering what I might try yo test it, it to find out how to figure this out. Any ideas are appreciated. Thanks

[enblethen]

Normal taillight converter is a 2 inch square about 3/4 inch thick.
It should have three wire on input side and two on output.
Some require 12 volt power and ground.
Tail light converter

[RandandDoug]

When I stated its not the brake controller I was just posting that in case someone was thinking it might be.

[RandandDoug]

Yes it has separate lights. Does the converter look like a big plug connector with a bunch of inputs and outputs, many of which are unused?

[enblethen]

I did not mean brake controller.
I meant a tail light converter.
Does MH have separate brake and turn signals?

[RandandDoug]

Not the brake controller. Disconnected that and everything still the same. And the fuse blows without the trailer being connected, so looks like I will be tracing the harness and connectors. And those connectors are how the maintenance folks stay in busibess, there us no rhyme or reason on the large ones with different entry points and different color wires on either side. Hopefully they can be hooked up without a master's and a 2000 dollar piece of equipment. Haha.

[enblethen]

Didn't you say earlier that the coach works and only the trailer connector have the issue?
You might want to check for hang nail in the connector.
Did you verify lighting configuration? MH have separte stop and tailights, Jeep have combined? If so could be bad tailight converter.

[RandandDoug]

Might try that but the odds of a twilight being shorted out on both the jeep and a trailer at the same time are probably slim.

[enblethen]

I would remove the taillight/stoplight lamps.
It could be a shorted lamp or socket issue.

[RandandDoug]

I believe I may have found the fuse related to the problems as it blows when I turn on the flashers. But it continues to blow probably meaning I have some wires touching somewhere.
One odd occurrence is when the flashers are on the brake controller readout dances around. I am wondering if I have a short in the plug receptacle or possibly the brake controller

[enblethen]

OP must have the functions that are not working turned on, not just ignition switch.
Another item to check is to see if you have a tailight converter installed in MH. If you have separate turn signals on MH and combined turn signals/brake lights on toad, you have a converter and it could have failed.

[dougrainer]

RandandDoug wrote:
Talked with spartan and on my year moho the same fuses that operate coach lights operate trlr lights. Coach is working properly so it is wiring or a connector somewhere. The receptacle looks ok, but I think I will start with replacing it with a new one in case it has funked out. Doubt that is it but a quick and easy try. Then trace the harness as far as I can.
When using a tester, should I hook the power lead to power and then to different contacts while those are turned on, brake, turnsignal, tail lights and so on?

Whoever you talked to at Spartan is wrong. For the past almost 20 years, Motorhome chassis makers (Ford/Workhorse/Roadmaster/Spartan/Freightliner) have ALL separated the Tow plug fuses from the regular chassis lighting fuses. They have done this to prevent a TOW short from taking out the regular motorhome lighting and Brake lighting AND to split the current draw to separate fuses. Running BOTH systems on 1 fuse would require larger fuses(over 30 amp on each circuit) and LARGER gauge wiring to handle that larger load. I NEVER trust the fuse panels schematic. You either use a voltmeter or a 12 volt tester(best and quickest) and check ALL the fuses in the 2 or 3 chassis fuse blocks. Make sure you have the Ignition key ON. Your problem is you have a towable fuse/s blown somewhere. Doug

[SoundGuy]

RoyB wrote:
ETRAILER has a couple of generic diagrams of what it should look like...

7-Pin Bargman Pinouts



Wire colour codes may vary from those indicated.

[Bobbo]

RoyB wrote:
ETRAILER has a couple of generic diagrams of what it should look like...

I picked one of those 7-way tester adapters from AMAZON that you plug into your truck 7-way connector and then you can do all of the truck functions and observe small led lights on the test adapter.

For me this was great as it eliminates any problem coming from the truck side... They make a 4-way test adapter as well...




All of my wiring fuses for this is on the truck side... The trailer does not provide any 12V power for the required DOT Trailer safety lights and functions.

Roy Ken

Or, get one that combines both:

https://www.amazon.com/Ultra-Tow-4-Way-Circuit-Tester-Model/dp/B00BINSI20

[RoyB]

ETRAILER has a couple of generic diagrams of what it should look like...

I picked one of those 7-way tester adapters from AMAZON that you plug into your truck 7-way connector and then you can do all of the truck functions and observe small led lights on the test adapter.

For me this was great as it eliminates any problem coming from the truck side... They make a 4-way test adapter as well...




All of my wiring fuses for this is on the truck side... The trailer does not provide any 12V power for the required DOT Trailer safety lights and functions.

Roy Ken