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steven2themax · 10-09-2010, 03:20 PM

Somebody please help me. I think I'm losing my mind.

http://www.youtube.com/watch?v=PiG5sQ0kl1g

(sorry the video is sideways!!)

Some background.

Towed the airstream from Tx to Wi earlier this year. All the lights etc worked. Initially I had a loose wire in the umbilical. The blue power line was resting on the right brake line. So the brakes turned on when I turned the signal on, but I fixed that.

Just dropped the pan and welded the frame. I am prepping for new axles and brakes.

Since I had all the brake lines available I decided to check them. Hooked the TV up to the trailer and got nothing. I took the umbilical apart and found the white wire was loose and reconnected it. Still nothing..no lights at all, no turn signals etc.

I checked all the fuses in the TV (diesel ford excursion). The 20amp trailer tow park lamp fuse was blown and I replaced it. Also the MAXI 30 amp trailer tow electic brake fuse had the top clear plastic cover missing. It still tested good, but I replaced it anyway.

Sat down behind the vehicle with a multimeter and found I had power to all the things I tested.

Plugged the 7 way in and still nothing.

Took the cover off of the 7 way fuse and still got no power indications that made sense (see video

http://www.youtube.com/watch?v=PiG5sQ0kl1g

). I noticed there was some corrosion on the white ground wire so I redid it. Also the blue power line was loose so I tightened it. Still nothing.

The discrepencies between what is coming through the 7 way umbilical and what shows up inside the trailer on the 7 way fuse box are so weird I made the video.

Please help. It is about to get cold in WI and we want to head south.

Steve

Ag&Au · 10-09-2010, 04:07 PM

Is the trailer hitched to the truck when you are making these checks? If not, run a wire from the truck frame to the trailer frame and see if things start working. It is possible, that the ground wire on the truck connector is not longer attached to the ground on the truck. Check with an ohm meter between the ground pin on the truck connector and the frame of the truck. There should be continuity. If that is good, then check between the ground pin on the trailer umbilical and the trailer frame.
If either of those is not showing zero ohms or close to it, then you will have to work back on the wiring to find out where the discontinuity is.

I know its not much help, but its a start.

Regards,

Ken

tphan · 10-09-2010, 04:18 PM

Another suggestion from Longmont, Co.- when I was remodeling my '72, I did something to kill the lights. It seems to me there might be a fuse inside where the trailer umbilical plugs in. In mine, it's down under the gaucho, inside a box of sorts. Another place to look for an easy fix, I hope you find it soon because I know how crazy this stuff can drive you! I guess my thought is that the frame welding shorted something out..... Good luck- tim

Splitrock · 10-09-2010, 04:47 PM

Hi Steve,

My trailer lights have a possibility of three power sources. Those all have to be isolated and tested. They are the tow vehicle, the trailer battery, and the converter.

There's three elements you're dealing with . . . and you have them all mixed up. The three are the tow vehicle, the umbilical cord, and the trailer. I separated mine and worked on one at a time.

First the tow vehicle: Test that without the trailer plugged into the 7-way with a 7-way tester available at most auto parts store. I bought mine at a farm supply store. It just takes one minute to see if all is well with the tow vehicle by looking at the tester and working the lights, signals, and brakes. Don't mix up the brake lights with the brakes.

Second is the trailer: With the umbilical unplugged, the battery removed from service, and the converter unplugged, test the 7-way with the same 7-way tester you used to test the tow vehicle. Plug it in where you plugged the umbilical to the trailer. Use the function chart appropriate to your trailer. Identify each wire according to function without respect to wire color. Test with a small battery charger. A helper is nice but I did mine alone.

Make sure everything works with the battery charger and is wired correctly according to the 7-way tester.

Third is the umbilical cord. I plugged mine into the tow vehicle and tested the pins with a jumper light grounded back to the tow vehicle frame. When the tow vehicle works without the cord, when the cord works without the trailer, and when the trailer works without the cord, it should plug in and go. Your video showed me how confused I'd be if I tried to do what you're trying to do.

Get to basics, test the components like the breakaway switch and don't take any shortcuts. Do what I wrote and it will all work the first time you plug it in, I guarantee.

Gary

steven2themax · 10-09-2010, 05:28 PM

Ok I grounded the AS to TV and no difference.

initially I had plugged the umbilical into the TV only and checked it. It seemed to work correctly according to the diagram I found. The bizarre thing is when I plug it into the trailer those exact pins that worked all of a sudden don't work.

When plugged into the trailer the blue power cord in the center has power when the trailer is plugged into 120v but none when it isn't.

Welding causing short makes sense.

How do I unplug the converter?

I looked for some fuses in the AS because the owners manual seems to indicate that there are some but couldn't find any.

I will buy a 7 way tester ASAP

Aage · 10-09-2010, 05:40 PM

When I first got Henri (my Sov) ready for the road, I couldn't get the outside lights or brakes functioning properly.

I called Andy at Can-Am RV, and after discussing what I had done to that point he told me to reverse the umbilical. That is, switch ends: plug the end I had in to the trailer into the TV, and vice versa.

It all worked.

I still don't know why the difference, but when that happened I marked each end of the cord so I would keep them straight.

**DKB_SATX** · 10-09-2010, 06:22 PM

Quote:

Originally Posted by Aage

When I first got Henri (my Sov) ready for the road, I couldn't get the outside lights or brakes functioning properly.

I called Andy at Can-Am RV, and after discussing what I had done to that point he told me to reverse the umbilical. That is, switch ends: plug the end I had in to the trailer into the TV, and vice versa.

It all worked.

I still don't know why the difference, but when that happened I marked each end of the cord so I would keep them straight.

I'm guessing that it made a difference for you because you had a custom umbilical that made the conversion between modern 7-pin pinout and the '74 Airstream pinout... so plugging it in one direction would work perfectly, the other would work strangely or not at all.

Splitrock · 10-09-2010, 06:38 PM

Quote:

Originally Posted by steven2themax

Welding causing short makes sense.

How do I unplug the converter?

I looked for some fuses in the AS because the owners manual seems to indicate that there are some but couldn't find any.

I will buy a 7 way tester ASAP

Hi Steve,

If there's a short, it'll be easy to find when you verify every wire by a wire by wire function test.

The converter is powered by the 110 volt shore power cord. Unplug that cord, and remove the trailer battery for testing. The only power you want for testing is a small battery charger or a jumper from a charged battery that's not connected to anything except the jumper wires. I use a bright 12 volt jumper light for testing.

Three things needed in addition to the plug plan I posted on your other thread: battery charger, jumper light, and a multi-meter.

The fuses for my trailer were mounted inside the cover to the 7-way plug inside the trailer. I did all my 7-way work from the inside with the front left panel removed so I could access the brake wires and the breakaway switch wires.

The 7-way trailer fuses had been removed from my trailer by a previous owner AND the breakaway switch had been disabled. I installed a new breakaway switch and installed a new fuse panel. I wired my 7-way to match the tow vehicle by using the 7-way tester and my umbilical cord is reversible as it should be. If the umbilical cord isn't reversible, something's wired wrong on one end or both. If the trailer is wired correctly and the tow vehicle is wired correctly and the cord is wired correctly, there's no way that cord isn't reversible.

The problem with not doing everything right at both ends is that it'll show up at the wrong time at the wrong place like when your cord is lost or stolen and a standard 7-way cord won't work. (I carry a spare cord) I'd rather sort everything out in my shop with my tools right on the bench and without any time pressure or people waiting for me.

Gary

steven2themax · 10-09-2010, 07:09 PM

Thanks gary what is a jumper light?

The TV and AS have distinctly different style connectors (both 7 pin) and cannot be interchanged. Umbilical has worked in the past but on both ends the screw that holds the shell on tight to the cord is stripped so I am thinking of replacing both ends.

Splitrock · 10-09-2010, 07:59 PM

Quote:

Originally Posted by steven2themax

Thanks gary what is a jumper light?

The TV and AS have distinctly different style connectors (both 7 pin) and cannot be interchanged. Umbilical has worked in the past but on both ends the screw that holds the shell on tight to the cord is stripped so I am thinking of replacing both ends.

Hi Steve,

A 12 volt test light looks like this:

Link: https://www.makariosrv.com/products/...est-Light.html

Search for: how to use a 12 volt test light

Your 7-way plugs will probably fit either way. Try it. The trailer side likely has a RV style 7-way and the tow vehicle has a blade style. They're reversible. The RV style is the best type in my experience and less prone to failure.

Tester:

http://www.youtube.com/watch?v=AOB_1...eature=channel

Gary

steven2themax · 10-10-2010, 10:15 PM

Ok correction. Just figured out the AS is 6 pin and the tv is 7 pin

Splitrock · 10-11-2010, 08:12 AM

Quote:

Originally Posted by steven2themax

Ok correction. Just figured out the AS is 6 pin and the tv is 7 pin

Scratch my reversible umbilical thesis.

steven2themax · 10-27-2010, 09:24 AM

Just an update. I did end up getting everything to work. Not really sure how I did that other than divine inspiration. The 7 way plug into the TV was a little loose so I replaced it. i rewired everything back to the way it was originally including an extra wire which I thought was redundant but turned out to actually make the brakes work. this wire was originally only wired to the street side brakes. I rewired it with 10 gauge wire to both sides.

Sadly at some point the trailer lights stopped working and I had to use hazards at night during our trip to GA. If anyone has suggestions on that it would be great. All the light work except for the running/tail lights.

Splitrock · 10-27-2010, 09:42 AM

Glad everything worked. When my tail/running lights didn't work, I checked the wire and ground at the 7-way, and then I replaced the clearance lights, and replaced all the bulbs in all the rear lights. While I had those bulbs out, I cleaned all of the sockets. When I tried it, everything worked.