Seeking some knowledge for locating the grounds associated with the Rocky Point conversion on my R75/5(fused). I've had this setup on my bike since purchasing the bike many years ago, no complaints however I recently had a smoke-out inside the headlight-bucket, cause unknown, yet primarily affected the horn circuitry ruining Grn/Black, Grn and other wiring in close proximity within the bucket and main harness. I decided to replace the harnesses, ordering from EME.
My question getting the connections involving what the deviations for proper ground I need to make from original schematic references. I've looked at the R.P. conversion diagram yet the grounding alterations are non-descript since now we have 2 plastic connector blocks in lieu of original setup. I am confused how and where to run my grounds(Brown)within the bucket, elsewhere I maintain the connection at the frame ahead of coils. Anyone that can give support to me with their experiences and also perhaps a template and/or pictures would be helpful, thx. Bill E #3809
Bill -
I know nothing about Rocky Point ignitions and very little about /5 wiring, but it sounds to me like that's not your problem anyway.
► The reason the harness "smoked out" is due to a short circuit. Usually a short circuit only blows a fuse to warn you, but the Germans in their wisdom leave a huge amount of the Airhead harnesses un-fused... a long time issue in the Airhead world. If you are smart (or simply tired of paying for harnesses), then I suggest you add a 15A flat pack fuse and water-proof fuse holder to the Red wire coming off the Positive battery terminal... and physically located close to the battery.
This because the Red wire runs all the way along the frame, into the ignition switch (and clock), and then exits as Green (ignition sys) and Gray (lighting sys). All 3 of those wires are totally unprotected within the stock wiring.
My question getting the connections involving what the deviations for proper ground I need to make from original schematic references. I've looked at the R.P. conversion diagram yet the grounding alterations are non-descript since now we have 2 plastic connector blocks in lieu of original setup. I am confused how and where to run my grounds (Brown)within the bucket, elsewhere I maintain the connection at the frame ahead of coils.
• The only thing that Returns (Brown) go to inside the headlamp shell is the headlamp bulb, via the 3-pin connector. If you have the all-in-one speedometer, then that's another Return inside the HL shell. (Unless you also use the "parking lamp", which due to 24/7 headlamps ON law is now useless.)
• All lamps will need a Return. That includes tail lamps, turn signals, and dash indicators.
• All relays will need a Return.
• The coils Return through the wire going to the points, not the metal shell of the ignition coil.
• Most everything else is attached to the engine block, and those Returns are taken care of by the battery cable to the transmission.
► To find your short before you re-connect the battery, look for the color wire that cooked. Green is before the fuse and un-protected; Green/Blk is after the fuse and should have been protected by an 8A fuse.
Hope these insights help.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Richard, that was an excellent response. The only thing I have to add, and I do have the Rocky point ignition in my /2, is that I ran my grounds to the two bolts/nuts on the sides of the headlamp housing.
Richard, that was an excellent response. The only thing I have to add, and I do have the Rocky point ignition in my /2, is that I ran my grounds to the two bolts/nuts on the sides of the headlamp housing.
The older the bike (or car for that matter), then the fewer the Returns you will find in the stock harness. Pre-1970 vehicles simply didn't include those wires. They bonded Returns to the motorcycle frame or car body. Of course after 5-8 years of driving on salty roads the bond failed and the electrical device started going flakey. Back in the early 70's you couldn't drive anywhere without seeing cars with 1 very dim headlamp. VW Beetles were especially bad about this.
Older motorcycles usually ran one wire to the headlamp shell because the ground Return through the headpost bearings was so very "iffy", but tail lamps were always grounded through the rear fender. It's just the way things were done. Since ~1975 Return wiring has been much, much better, with Brown wires running to almost every component.
When you own Classic or Vintage machine, it is not enough to bring the piston rings and valves up to modern clearances, it is also incumbent upon the owner/user to update the electricals to year 2023 standards. This is one reason I keep harping about the electrical anti-oxidation compounds. People forget that back in the pre-1970's sometimes people had to walk home!
That doesn't cut the mustard with today's riders. 🤣
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
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