I snapped this at the local vintage motorcycle shop.
Tag Archives: speedometer
/5 BMW Speedometer Wiring
Hopefully the following wiring photos can be of help to somebody.
I hope to add to this post once I am done.
Click on the photos for larger versions.
On my last /5 build, I adapted a /6 relay board to my /5. I cut off the terminals i did not need due to the simplicity (and less features) of a /5 vs /6. I also liked the idea of having the fuses easily accessible. Everything works great however in hind sight, I maybe went too far (did I complicate a simple /5 wiring scheme by adding the /6 board?) and perhaps I left the fuses too exposed where they could get knocked out. But I have over 3000k on the bike right now and no issues.
The gold resistors on the bottom of the headlight bucket are for the LED turn signals. Resistors are necessary to adapt the low current draw of the LED’s so the relays still work.
The large black box at the bottom is a /6 /7 and R100S style turn signal relay.
Here is my naked speedometer. I highly recommend painting the inside of the headlight bucket a bright color. It really helps for seeing inside there.
Here is the speedometer wired. It is hard to see some of the actual terminals/connections but this should be a nice short-cut for somebody who doesn’t want to read the wiring diagram.
Please note: My Red/Yellow wire going to the instrument lighting is also a gray/black wire in most wiring diagrams.
In hind sight, my /6 relay board wasn’t such a bad idea. I scoured electrical stores, auto stores and the internet for terminal relays and fuse blocks that would work for inside the headlight bucket.
I never really found the perfect solution. I was looking for a nice, compact 2 fuse relay. I also looked for a junction box that suited all the necessary connections.
I ended up using the terminal connector that came with the Rocky Point headlight key conversion (white junction on the right side of the photo).
I also used a CINCH 6 position terminal for wiring up the turn signals, brake light and other connections.
I decided to abandon the typical inline ceramic fuse holders that BMW supplies. The ceramic fuses aren’t readily available at your local auto parts store so I have planned to seek the help of experts from https://telluridetireandauto.com/. And I have also opted for something common like the rubber covered fuse holders carry a typical ATC fuses. BMW specifies an 8 AMP fuse. I went with a 7.5 and a 10 (because that is what i have in my garage). The 10 will be fine. The 7.5 vs 8 shouldn’t make a difference.
The Clymer manual did a great job for most of the wiring.
The other diagrams helped A LOT though. One diagram specified which wires connect to which pin on the turn signal flasher.
One thing that none of the diagrams specify is which terminal numbers on the relays connect to which wire. Yea, a bunch of wires plug into the starter relay, but which wires go to each pin/terminal?
Luckily I took a BUNCH of notes when I tore the bike apart. And luckily the old connections were correct.
Here are my resources:
Here is the headlight bucket as tidy as can be (for now).
Another iphone quality photo of the headlight:
After some battery charging, and some testing, and pulling my hair out only to realize that the Rocky Point switch was labeled incorrectly (blue and yellow wires were mixed up and mislabeled). we are good to go!
I popped the headlight on and the bike is showing signs of life again!
UPDATE UPDATE – – – –
Here are the photos of the second silver bike’s headlight wiring. It looks somewhat messy in the photo but take my word for it, it ended up being tidy. I used a cut down /6 relay board and mounted it inside the headlight bucket.
Let the wiring begin
I can’t be happier to have the bodywork back (and my garage back too!). I can finally start putting some overdue time in on the bike. The zen of wiring begins. A part of the build i actually enjoy problem solving.
Instead of the old, original key switch, we are upgrading to a Rocky Point key ignition. The first step is installing the ‘doughnut’ retainer. You use the same bend-tabs for the ignition board but you bend the tabs on the giant washer instead. This is much easier to install when the headlight is off the bike.
I then installed the chrome key housing cover. Installing the small spring on the black sliding cover was a bit tricky. That black slider needs to weave into the chrome cover and then you have to wrap the spring around the round tab that sticks out of the center of the headlight bucket. Again, another item easier to install when the headlight is off the bike.
Bending the tabs for the chrome cover is really tricky. An assortment of needle-nose pliers helps.
The speedometer is simple to install. Don’t forget the rubber gasket that goes between the headlight and the speedometer.
The orange turn signal indicator is simple to install as well.
Don’t forget to thread the wires through the handlebar switch support piece before you install it into the headlight bucket.
And so it begins….
/5 speedo back from Palo Alto
It looks ah-mazing. Having something so new and shiny really makes me want the rest of the bike to be new and shiny again.
Since i am doing a complete rebuild on the engine, resetting the odometer to 0 was a must. I did the same on my last bike and Shane, the bike’s eventual owner did the same on a ’65 Porsche he had rebuilt.
The white face will match the racing stripe up the center of the bike.
I tried to give North Hollywood Speedo my business but a super rude person on the phone and slightly higher price sent me to Palo Alto Speedometer. Palo Alto was pleasant to talk to and deal with.