Help on wiring brakes please! UK novice in trouble

[John Keith]

I'm here in the UK trying to figure out the brake circuit for my 1963 Bambi. Since electric brakes are very uncommon in the UK there's no local expertise to call on, so it's you dear reader or nothing!
The car has been wired for electric brakes and there 2 red wires ready at the back for the trailer to plug into.
There's 2 (same colour) wires coming out of the back of each hub and these have seperately each been joined with the 2 from the opposite hub together producing 2 wires presumably to connect to the 2 from the car. Since there's no common colour coding will it do any damage to connect anyone to anyone? If not how do I tell what to connect to what?
The next problem I have is with the (new) breakaway switch. It has a red and black wire coming from it. I have dispensed with All the old wiring on this Bambi as it is in such poor condition (and the UK system is 240 volt not US 130) so the question is what to wire the breakaway switch to (presumably the battery which I'm installing), and the hubs to effect the breaking in the event of a breakaway.
I'm not an electrical expert but I have re-wired 4 houses in my time without creating fire or blowing myself up! (It's not legal in the UK to do it now....). Your help would be really useful and I can guarantee a free nights accomodation here in the UK Lake District if you're ever round this way. I hope eventually to tow this Airstream with a Czech Tatra 603 State limousine which has an aircooled V8 in the backend. That will be really cool, but we need brakes first. regards John B. Keith

[Ganglin]

See if this diagram helps you any.

[markdoane]

John,

Welcome to the Airforums. Hope you enjoy your Tatra tow vehicle. I haven't heard of anyone using that for a tow vehicle.

Regarding the brake magnets, there is no polarity to the wires for the magnet, so it doesn't matter which wire goes to the brake controller and which goes to ground. It sounds like you have the magnets correctly wired in parallel, not series.

The breakaway switch is connected with one wire to the 12V battery, and the other tapped into the brake circuit.

Which brake controller are you using? Some models do not like to have voltage applied to the brake line, so it is a good idea to disconnect the umbilical line before testing the breakaway switch.

[bullydogsmom]

John, welcome to the forums. Your tow vehicle will be very different. We have a friend here who is from the Czech Republic, and he collects Tatras! He has a great collection of about 5 of them now, and I'm sure that the collection will continue to grow. If you need an help on the Tatra let me know, I'll pass on his email address.

Annette

[richinny]

since this is new to you, i'll just confirm that when you say that the car was wired for the electric brakes, you do mean that the car has a brake controller wired for the trailer, don't you?

[Lumatic]

Ditto there is no specific + or - wires for the brakes. It does not matter how it is wired as long as one is + and the other - (ground). In most Airstrams I am familiar with the trailer brake ground is wired to the 7 way connector and the tow vehicle ground. The ground wire is also wired to the frame. Another option is to wire the individual brake ground wires to the shell or frame. The ground to the tow vehicle will then be through the hitch, but it is a good idea to also have a wire connection from trailer to tow vehicle ground wire. Does your Bambi have a battery in the trailer? Some older Airstreams do not. The break away switch needs a battery to activate the brakes. Some breakaway switches have their own small battery. If you test the breakaway switch make sure to disconnect the connection to the tow vehicle or you may ruin your brake controller. Also don't count on any of the existiing wiring being installed correctly.

[John Keith]

Thanks that's a great help. If your ever in the North of England please free to contact me, regards,
John Keith

[John Keith]

Thanks that's a great help as I must connect the brake wiring today before I fix the new undershroud. If your ever in the North of England don't hesitate to contact me!
John Keith

[John Keith]

Thanks that's a great help. If your ever in the North of England don't hesitate to contact me
Regards, John keith

[John Keith]

Yep my tow car has a brake controller bought in the US of A and wired to instructions. Also the breakaway unit came from Chicago. So I think I've got the right stuff fitted.
Regards,
John Keith

[John Keith]

Thats very useful information and thanks for taking the time to reply, If your ever in the North of England don'y hesitate to contact me,
Refards,
John Keith

[John Keith]

Annette, your friend is very lucky to have found 5 Tatras in the US. The best collection I know is the Lanes Motor Museum in Nashville. They have the finest collection I've seen outside Koprovice (which is where they were made and where the Tatra Museum is based). We have an elite band of Tatra owners in the UK. Mine needs a repaint which it will get in between my restoration of the Bambi, a 1902 Oldsmobile, a 1926 Chevrolet, a 1927 Austin, a 1934 Triumph Super 8 (unique), and 2 x 1934 Triumph Southern Crosses (only 8 left worldwide). The 1967 Triumph Vitesse (6cyl, open top) is a goer!.Don't know how I found time to go to work......
Regards,
John Keith