Posted 2020-09-14 7:42 PM (#173242) Subject: 1997 Bison 2 horse BP trailer help- brakes and electric.
I recently purchased an old Bison trailer and am discovering they don’t have a great reputation. This one fit our budget and our goal is for it to transport goats.
I am having a problem getting the brakes to work. The wire harness plug was switched over to a 7 pin connector and I think I am having ground issues. I’m curious if any of you would know where I could find a wire diagram and how how to start trouble shooting this. I’m pretty mechanicaly capable but don’t have much experience working on trailers.
Thanks in advance for any help you may be able offer.
Posted 2020-09-15 8:27 AM (#173244 - in reply to #173242) Subject: RE: 1997 Bison 2 horse BP trailer help- brakes and electric.
Look here- https://horsetrailerworld.com/home/wiring.asp Your trailer shiould be a pretty nice sound trailer. The only similarity to the current Bisons is the name. Different ownership, different factory, different everything. Fix it up, and enjoy it.
If the link doesn't work, look at the bottom of the homepage for Horse Trailer World.
Posted 2020-09-16 1:53 PM (#173248 - in reply to #173242) Subject: RE: 1997 Bison 2 horse BP trailer help- brakes and electric.
Thank you RTSmith!
That was very helpful. The trailer seems to be in great shape, a bit of rust here and there on the body but the frame is good. Something is definitely going on with the electrical.
Thanks to your link I discovered part of my problem. The wiring harness has 6 wires that someone converted to a 7 pin plug. When I opened up the plug to see what was connected to what, I was shocked that only 3 wires were hooked up. The other 3 were folded away.
The red wire was hooked up to my right turn signals, the blue wire was hooked to my left turn signals and the brown was hooked to the tail lights. The black (hot), the white (ground) and green (my brakes) were folded away.
Do different manufacturers use different color wires instead of a universal code? I thought it was odd that my red was right turns while blue was left turns and green i think is my brake. According to the link you sent red would be my left turn, green would be my right turn and blue would be my brake.
The breakaway kit I think is a mess, i plan on replacing that. But it would explain why the breakaway lead was spliced into the green wire further down the harness.
Another question I have is why doesn't my break controller in the truck light up when the trailer is plugged in? The breaks do not seem to work. Any ideas on how to start trouble shooting those?
Posted 2020-09-17 6:24 AM (#173251 - in reply to #173242) Subject: RE: 1997 Bison 2 horse BP trailer help- brakes and electric.
Yes- back in those days there wasn't necessarily a common color code. In fact some smaller manufacturers would sometimes use all 1 color, because they got a deal on a bunch of it.
What you need to do now is identify your wires by function. Using a battery, ground it to the trailer (jumper cables work well). Then lightly touch each wire to the + post and see what activates. Hopefully you can identify the ground by eye, that way you aren't getting all the sparks. Once you know each function, you can put them into the 7 pin male plug where apprpriate.
And yes, when that trailer was made it had a 6 pin plug. Thankfully those started to disappear around 2000. They didn't necessarily have a standard wiring diagram either.
Oh- and the color codes were different from the 6 pins to the 7 pins. Just to confuse things. Also- it sounds like your brakes & ground (it is grounding through the ball. Works, but not the best option), aren't hooked up. The third wire may be an accessory circuit for interior lights.
Posted 2020-09-18 6:27 AM (#173254 - in reply to #173242) Subject: RE: 1997 Bison 2 horse BP trailer help- brakes and electric.
I think i have everything sorted out.
My next challenge is to get the brakes working. I must have a short or corroded wire somewhere. Im going to start with the crappy connectors above each wheel and see if i get lucky.
Ill keep you posted on my progress
Posted 2020-09-18 10:16 PM (#173256 - in reply to #173242) Subject: RE: 1997 Bison 2 horse BP trailer help- brakes and electric.
Location: North Carolina
If your ground is through the ball... Change it. Worked on a friend's trailer that was an electrical nightmare. Sometimes it worked and sometimes it didn't. Finally traced it to the lack of ground in the connector. The ball / hitch is a poor ground since it moves. a little grease makes it worse.