I've noticed some irregularities in some of the factory drawings and I'll list them here in this post.
73-74 wiring diagrams:
I've been trying to track down the "Fuse Wire" that shows up in the -78 FSM diagram on the XLCH drawing.
It is noted on the XLCH drawing but is not noted on the XL drawing.
However, the connector for it is present on both drawings in their installed positions.
The Doctor71 brought my attention to Service Bulletin #659. I added more info to that in the service bulletin page in the Sportsterpedia:
http://www.sportsterpedia.com/doku.p...artsplus-01bL:
A 2“ long 20 gauge wire (70105-73) was added in the wiring circuit on FL,FLH, FX, FXE, XL and XLCH models to act as a fuse wire.
The fuse wire protects wiring between the battery and the lighting, ignition and accessory circuit breakers.
Because the motorcycle wiring is heavier gauge, this fuse will burn out first in case of a short or overload and open the circuit.
Caution: Do not use heavier gauge wire for a fuse wire. In place of this HD part, any 20 gauge braided wire will work also.
Before replacing the fuse wire, check for short circuits in the wiring and ignition switch to determine the cause of burnout.
When troubleshooting the electrical system for loss of power, check this wire for burnout at the following locations;
FL/FLH: The fuse wire is connected to the starter relay terminal (#1) and to the connector in the conduit leading to the battery positive terminal.
FXE: The fuse wire is connected to the starter solenoid (long) terminal and to the connector in the conduit leading to the starter relay tan wire terminal.
FX: The fuse wire is connected to the battery positive terminal and to the tan wire connector in the conduit. The tan wire terminates at the "B" terminal on the ignition switch.
XL: The fuse wire is connected to the regulator "BAT" terminal and to the red wire connector in the conduit leading to the starter solenoid (long) terminal.
XLCH: The fuse wire is connected to the battery positive terminal and to the red wire connector in conduit leading to the regulator "B+" terminal.
Attached below is the service bulletin #659 (3 pages).
Attachment 20626
Attachment 20627
Attachment 20628
Here is the link to the fuse wire pic at NOSParts:
https://nosparts.nl/cgi-bin/dbsql/db...umber=70105-73
The fuse wire doesn't show up in the -74 FSM but does in the -78 FSM.
Neither the fuse wire nor the connector (#35 in the -78 FSM) for it show up in the parts catalogs or supplement catalogs thru -78B.
But the wire itself can be seen at NOSParts.com.
The pic shows the wire skimmed on each end for connectors though.
Looking closer at the wiring diagram, connector #35 also shows up as a splice tap on the green wire coming off the turn signal flasher.
So it appears they simply cut the red wire and used a splice tap on it inside the conduit to install the fuse wire inline at the factory.
As to 'connector #35', the FSM wiring diagrams do not distinguish between what type connector they refer to.
It seems they are not refering to a specific part or type but rather denoting a wire splice of sorts.
#35 is designated for the fuse wire, TS flasher, ignition and turn signal lamp wires (some years) etc.
But, going beyond the manual, it has to be small enough to fit inside the wire jacket or conduit without hindering the other wires beside it, especially with the vibration.
Since it doesn't seem to show up in the catalogs specifically for the fuse wire, it could be as simple as a small folded piece of steel.
The TS flasher connector appears to be an permanent 3 way tap as should be the fuse wire with a permanent 2 way.
By permanent, I mean a crimp connector instead of a 2 piece socket.
The connectors in the parts books look to range from crimp types to plastic housing punch connectors and simply listed as 'connector'.
If the fuse wire connector could fit in the jacket (like the 75 wire does) then it can't take up much space, as a socket connector would, I'd think .
Due to positioning, it would need to be a structural sound connection.
The TSB does not require dealers to retrofit this change to previous models.
And that splice tap is probably what they are referring to in the service bulletin.
I've added a reference to the service bulletin on the "L73 Fuse Wire" on the 73-74 drawings.
And also cropped out these drawings for added emphasis on the existance of the fuse wire.
edit:
The handlebar ground is listed in the -76A parts catalog being for L73-up XLH/XLCH.
It also is listed in the -74 supplement catalog for L73 models.
Yet the wiring diagrams in the -78 FSM show only show it starting in 1977.
So I'll add that to the drawings also.
75-76 wiring diagrams:
The splice tap for the fuse wire is present in both these drawings but the wording "Fuse Wire" has been omitted on both drawings.
So the fuse wire was also present on 75-76 models.
On the 75-76 XL drawing, the connector is on the wire between the starter solenoid and the starter relay and appears to connect to the relay.
(red wire is denoted at the solenoid)
I've also shown the fuse wire on the main wiring diagram and added a reference to the service bulletin.
And also cropped out these drawings for added emphasis on the existance of the fuse wire.
77 wiring diagrams:
The fuse wire was replaced with a main circuit breaker in 1977.
Connector #35 is still shown in the wiring key for the splice tap at the turn signal flasher.
Tthe 30 amp (main) breaker (74599-77) doesn't show up in the 77 supplement catalog although it is in the 78 FSM drawing as being installed on 77 models.
It doesn't show up for parts order until the 78 supplement (October 1977 ( 78 year model season)).
And even then it shows up for 78 to * - XLH, XLCH (not 77).
-78B shows it for 78 models.
So E77 models should have come with the fuse wire.
The only reference I have thus far to a main circuit breaker being installed on a 77 Sportster at all is the -78 FSM wiring diagram.
78 wiring diagrams:
The solid state regulator came out in 78 and the hookup for it changed to a plugged set of wiring.
Yet the 75 fuse wire was being sold for 78 models also.
So there may be some E78s that came with the fuse wire and older regulator.
Reference the XLFORUM'S Sportsterpedia
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