vintage brake circuit

[wildcat455]

Just got a call from my mechanic, he's replaced the backing plates, greased the bearings and put new shocks on my 61 Overlander. He's also replaced the old wiring pigtail and connector. Now the problem, there is a short in the brake circuit. Assuming everthiing is hooked up external ok, where do we look next without pulling the pan? The tail. brake, running lights all work fine. Thanks. Mike

[Pahaska]

There is absolutely no connection between the brake circuit and all of the other lines that you mentioned.

Does the trailer have a breakaway switch? If so, is it actuated or failed? Is it perhaps shorted out in the umbilical plug or cable? That happened to me once many years ago.

If not the breakaway switch or umbilical plug, there isn't much to look at. The circuit goes from the pin in the umbilical plug to a terminal block in the very front of the trailer. There, it is joined by the wire from the breakaway switch (if present). From the terminal block, there is a wire to each brake pigtail. The other side of the pigtails are wired to ground. Polarity is not important.

Only the wires from terminal block to brakes is inaccessable. It would not be difficult to simply unhook these wires and put in new wiring on the outside. If you do, keep the lengths to the various brakes fairly equal. length

[overlander64]

Greetings Mike!

I hope that you have better luck than I did with my '78 Minuet. It was experiencing the same kind of trouble, and it was found that someone in the past had worked on the brake wiring and one of the wires was pinched between the underbelly and the frame - - dropping the belly pan and rewiring the brake circuit solved the problem.

It may be far less involved, however, if your mechanic wasn't familiar with Vintage Airstream wiring and didn't check ont the function of each wire when the umbilical cord was replaced. The color codes used on Vintage Airstreams, as you may be aware, do not correspond to the modern standard. The link below is to the wiring code used by 1960s Airstreams:

Airstream 1960s Umbilical Cord Wiring Colors/Functions

The date on the above code is 1964, but it is my undestanding that the wiring colors were similar for 1961. If you compare these colors to their current use, they don't necessarily correspond. The current color codes are shown in the link below - - scroll down the page about half-way to find the actual diagram.

Current Standard Wiring Color Codes

I know that the problem with strange happenings with modern tow vehicle wiring versus original Airstream plugs is a frequent issue for recently acquired unit - - this may not be the case with your problem, just a thought about a potential cause.

Good luck locating your gremlin.

Kevin

[wildcat455]

I'll have him re -check the breakaway, I was planing on replacing it anyway. There are two small access panels near the floor under the couch in the front each above one of the frame members. Is either or both of these the access to the terminal block you mention?

[wildcat455]

thanks Kevin, I'll print the diagram and give it to him. Apparently the old umbilical had been previously replaced, it had the blue brake circuit wire color instead of the yellow i see on the 60's diagram. I'll double check to see that he connected it correctly. I do know that he found the wiring to the breakaway switch 'funky' his words, so i'm going to have him check that out too. I'd prefer to avoid dropping the belly pan, my experience in remodeling houses has led me to believe that exposing that much area is going to lead to many many expensive projects. I'd prefer to stay focused on brakes for the moment. If I get the belly exposed, then i'm off on new grey tanks, replacing insulation, rewiring, who knows where it will lead!

[Pahaska]

Originally posted by wildcat455
I'll have him re -check the breakaway, I was planing on replacing it anyway. There are two small access panels near the floor under the couch in the front each above one of the frame members. Is either or both of these the access to the terminal block you mention?

The terminal block is above the floor against the front wall in every case that I have seen. I can't guarantee yours is there.

[overlander64]

I believe that the junction box for the umbilical cord wiring in the 1960s coaches is accessed through a rectangular panel in the bellypan just behind the A-frame of the hitch. The access panels under your couch may be an alternate means of reaching the umbilical cord wiring junction box. I believe that the 12-volt circuit panel (glass house-type fuses if original) for the coach is usually on the front wall below the center window if my notes are correct (prior to '64) - - that places it near the original location for the battery centered below the front window in an exterior aluminum box.

Good luck locating your brake gremlin!

Kevin

[wildcat455]

I appreciate all the help and replies. Kevin, I'm a bit confused now. My 61 Overlander is before the univolt. I have two seperate systems, 110 and 12 v. There is the usual 110 volt circuit breaker box in the curbside closet. I've not seen any kind of access behind the couch, under the front window, only the two small 4x4 in removeable covers close to the floor, approximately where the A frame would be underneath, one above each frame member. I do have an fuse on the battery but that's the only 12 volt fuse I've seen. Guess I need to remove the covers, see what lurks beyond. Thanks again. Mike

[overlander64]

While I haven't seen the '61 version, in the '60 Overlander, the twin glass house-type fuses were behind an access panel on the front wall below the center window - - the fuses are not automotive as we would expect today - - rather the screw-in glass type found in houses of the period. It is very possible that a previous owner may have modified this as it was a peculiar arrangement whose purpose wasn't necessarily obvious.

Kevin