I may be jumping into the deep end without my floaties, but I need some information on wiring diagrams that show the junction block (as it actually looks), and the wire colors and which wire colors go where. In order to paint the bucket, it must be removed, so all wiring must be taken out. BTW, in my ignorance, I wondered WHY BMW engineers even used this block, and why they put it in such an undesirable location? Aside from two fuses and a tiny resistor, all it does is directly connect wires with spade fittings. Oh well...moot point made out of frustration. Anyway, I made a couple of mistakes while removing and marking my wires and I cannot find any illustrations that show what I need. I made a drawing of my board (attached photo), and was labeling and marking where they were plugged onto which spade while I was working (sweating), but inattention to my duty faded to a vision of how great a cold brew would be in my 99 degree garage, so I gave in to the beer idea and lost track of everything else. Surely one of our members knows where I can locate what I need, or has made a similar illustration for themselves, so, if anyone can guide me, I really would appreciate it.
Relax ! Have another beer ! It's not nearly as difficult as you may imagine.
The colors on the board directly correspond to the wire colors to be used on that terminal. For example, the 6 connectors in the lower RH corner are surrounded by Brown color on the connector board. That's where you connect all the Brown colored wires. (Brown is system Return, what most people call "Ground".)
• Now you need to realize that in this instance you may not have 6 Browns to completely fill all the prongs on the board, but that's OK. Every wire has a terminal, but not every terminal has a wire. In your future wiring, you may need to add a phone charging outlet or some such, and now you know where to find a good "grounding location".
• A lot of the colors are dark and muted. I highly suggest working under a bright white light so that you can see the true wire colors. Blue/Black will look a lot like Blue/Green, and even Dk Green, in regular light.
• Before plugging the wires and fuses back into the board, I highly suggest coating every terminal... especially the 4 fuse prongs... with a paste that will help you make better connections and seal out water. I suggest a product sold on Amazon called No-Ox-Id. It just takes a tiny bit on every terminal to restore a perfect connection.
Hope this helps.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Well, now I'm lost in my beer bucket celebrating the resolution you have so grandly given me! What a simple answer that I never saw with my simple mind. I'm off to Dallas this morning, but when I return, I'll tackle this challenge to see if I can reassemble this mess correctly after completing the painting of the bucket. I see that I'm going to have to cut at least four wires to be able to remove wiring from the bucket, and plan on using solder and shrink tubing rather than crimp connectors in the reassembly. Thank you so much for your help! I may be asking for more favors later on if I run into more "Lost In The Bucket problems. Keep the tank on top! The Old Hippie.
I see that I'm going to have to cut at least four wires to be able to remove wiring from the bucket, and plan on using solder and shrink tubing rather than crimp connectors in the reassembly.
Don't cut any wires !!
Further investigation with a bright lamp will show you rubber grommets that (after a shot of silicone spray or ArmourAll) will pop out and give you the access you need to pull the wire ends through without damage to the harness.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Well, I think a former owner messed in my bucket because it looks like 4 wires have metal connectors squeezing them together (picture). Or is the way BMW did it? I felt for connectors within the protective sheath but did not feel any, so I think the crimped connectors are what someone else put there in the past? I left the shrink tubing on two wires and removed it from two so you could see both looks.
I'll wait for your reply to cut or not to cut if there is an alternative to this. Later
Well, hold the phones. I felt the lines through the sheath some more and "found" some more lumpy things. I slipped the sheath back and found MORE splices even farther up the lines on the OUTSIDE of the bucket! Looks like this poor orphan has led quite a neglected and abused life while dufuses as mechanics, and I use that term loosely, attempted to maintain it (on a good day). Waiting on your suggestions.
Those spices aren't stock. Some previous owner or owner's mechanic added those. But I got to tell you that looks like professional work compared to some of the wiring I've worked on.
So your answer is probably somewhere between repairing what you already have and buying a lot of new parts.
You gotta do what you gotta do.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Ok...That's kinda what I thought, so, looks like I'm in the rewiring business for a while. That's OK too because I need to bring out those old soldering tool skills for a while. Also, this club would not be as great a place as it is without the good guys like you who so unselfishly help people like me who would be lost without you. Thanks a bunch, and keep the tank on top!
I think i have found one of the reasons there are so many splices in the system on this orphan. Some former owner installed one of those blazing saddles flame throwing headlight systems on the bike. There were so many extra components to the system in the bucket, they had to move all relays and other space robbing components of the stock system to under the tank! Arrrrgh! And whomever did it just used whatever color wires they had lying around, so nothing matches the wire specs called for on the schematic. I'm gonna be good at this before it's all over. BTW, is there a supplier who vends BMW wire color combinations. Thanks. ALSO, I have removed the torch headlight system and am willing to trade someone even for a stock system. I like original stuff. Later, and keep the tank on top!
Needing the space helps explain why the wires were fooled with at the outset. And that's worth something.
We're sitting on the trailing edge of the "DIY Motorcycle Home Improvement Era", and now it's easy to sit back and laugh. But back in the 70's and 80's, BMW newsletters were full of electrical mods that were considered common sense upgrades. My own RT had the 2 fuse holders re-located to the hollow frame tube just in front of the tool box.... again using common lamp cord. Another owner had also installed a CB radio and an AM/FM/Cassette player in the RT's side pockets. Through a series of relays, the CB overrode the rider/passenger intercom, which in turn overrode the music. Then there were sockets provided , because both helmets were hardwired to the system. (This obviously pre-dated Bluetooth and cell phones.) This "audio system" was all wired on the bike with solid core 4-conductor phone wire, like Ma Bell used to wire your house. Then, the fairing was studded with extra parking lamp bulbs, where the owner simply drilled tight-fitting holes and pushed about 6 wired bulbs into place.
I used to have a photo of the 2-foot diameter x 6-inch deep pile of wires I removed from the bike... just to start troubleshooting my new ride. Other owners will have similar tales, so we're right there (laughing) with you. Just realize that when you get a motorcycle that has lived through 40+ years, you simply have to expect to find some modifications from 10 or more prior owners.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Sounds like you have a mess on your hands. The wiring on my bike which I'm currently restoring was also a mess.
I ended-up buying a brand new main wiring harness(and all the sub harnesses). Hooked it up to the circuit board matching colors and it worked perfectly the first time out! No grief.
Bench Mark Works sells them at about half the price that MaxBMW does.
Also consider buying a used one off eBay. There are people the part-out bikes and you should be able to find a nice one cheap.
If you do decide to replace your harness make sure you document the path it takes from inside the headlight all the way down your frame. Photos, photos, photos! They're priceless.
Thanks so much! Actually, I found wiring the right color combinations that I needed that I got off of a Volvo at the wrecking yard here locally. It was even in the correct Guage and maybe a little heavier. Have found the correct information on an Airheads website that gives the wire functions by color, and I found the best schematic that actually shows the wire colors as they REALLY ARE and not those little bitty dashes of color that you still aren't really confident what color they are. Thanks for the auggestions, and later, ill try to post the Web sites for the In formation I just mentioned. Ride smooth and always keep the tank on top!
The locations for the wiring info are as follows:
On the Airheads home page, go to Forum, Wrenching, in search box, type "wiring", then press go. The wiring info is called "Wiring Color Codes" by Joe Glowacki, and he gives the best information that would enable anyone with wiring questions to solve them. The great schematic that I mentioned is by Gordon Wright. I just Googled, "Wiring schematic for 1976 BMW R90/6", and found his just by scrolling my way through them. Anyone working on the electrical system on their old Beemer should have this plastered on their workshop wall! Remember, keep the tank on top!
Another challenge. Horn does not work. So test the brown/white wire and the green/black wire from the button and it closes. Horn works with small jumper wires from batt. So, since the schematic I'm using shows the green/black wire goes to the 86 terminal on the starter relay, I go there to check to see if it is plugged in and clean. Well, surprise, but there is NO green/black wire going to the starter relay! On this bike, there is a green/blue wire on 86. One diagram I am using has a green/black wire going to 85 on the solenoid and a blue/yellow to the 86 on the solenoid, then it shows it going to the 85 spade on the fuse block, then to the starter button! Further, another diagram I have has a brown/yellow wire on the 85 solenoid terminal that goes to the starter button? I know you cannot know how to resolve this problem long distance, but any suggestions you may offer would be appreciated.
The horn has its own relay. The Starter Relay and the Horn Relay may use the same power source (a common fuse), but the horns are not using any part of the Starter circuit.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Advertisement
