Differences

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--- techtalk:ref:elec30 [2020/02/08 19:00]
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 ====== Ironhead Wiring Mishaps and Meltdowns ======
 \\
+See also illustrated [[techtalk:ref:elec07|1959-1985 Sportster Main Wiring Diagrams (created with reference to the OEM manual)]] in the REF section of the Sportsterpedia. \\
-It's important to have some sort of fail safe mechanism whether a fuse wire, fuse or circuit breaker inline between the battery and the voltage regulator. \\
+It's important to have some sort of fail safe mechanism whether a fuse wire, fuse or circuit breaker inline between the battery and the voltage regulator. ((The Doctor71 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/198978-ignition-wire-meltdown-74-xlh-and-hd-service-bulletin-659#post4376553)) \\
-Else you can unsuspectingly experience a experience a dead short, melted wiring or even watching your bike go up in flames (literally). \\
+Else you can unsuspectingly experience a dead short, melted wiring or even watching your bike go up in flames (literally). \\
 It appears that HD's quick fix in 1974 to the meltdown was Service Bulletin #659 adding a fusable wire inline from the battery. \\
 [[techtalk:ih:elec02#fuse_wire|Clich here to see more on the fuse wire]] in the Sportsterpedia. \\
 It's important to have some sort of protection on the main circuit. \\
 If it applies to your ride, you can ward off a potential meltdown in multiple ways. Do whatever works for you:
@@ Line 17: / Line 16: @@
   * Installing an inline fuse.
   * Or all of the above.
 ====== Broken Horn Bracket ======
+The horn bracket that is mounted along with the key switch between the cylinders has been known to cause meltdowns. \\
-Horn brackets that are mounted along with the key switch between the cylinders has been known to cause meltdowns. \\
+The fact of the bracket breaking (due to being loose, vibration, age etc,) isn't the problem (electrically speaking). \\
-The fact of the bracket breaking (due to being loose, vibration, age etc,) isn't the problem. \\
 The key switch terminals are bare ended (no insulation). \\
 Should the horn bracket break, the horn will (most likely) swing down & rest on the back of the ignition switch for awhile, shorting the terminals. \\
@@ Line 32: / Line 25: @@
 At this point, the motor is dead, no lights, no nothing. You're stranded on the side of the road, wondering just what happened. \\
-This happened to a 74 XLH all initially started by a broken horn bracket: \\
+===== The Doctor71's 1974 xlh =====
-This particular bike did not come with a fuse wire installed from the factory. So the main circuit was unprotected. \\\\
+This happened to my 74 XLH and all initially started by a broken horn bracket: \\
+This particular bike did not come with a fuse wire installed from the factory. So the main circuit was unprotected. \\
 See the 'before' pic of the horn / switch brackets below (taken ≈ 8 months prior to my catastrophic event). \\
 The ends of the ignition switch wires were heat-shrink'd immediately after this pic was taken. \\
@@ Line 42: / Line 36: @@
 For the fix, I added a reinforcement to the horn bracket & TIG welded it up, replaced all those wires, & added my own fuse wire. \\
-Before pic. Note the relative pristine condition of the horn mounting bracket, p/n 69129-72. ((photo by The Doctor71 of the XLFORUM http://xlforum.net/forums/showthread.php?p=5805036#post5805036)) \\
+Before pic. Note the relative pristine condition of the horn mounting bracket, p/n 69129-72. ((photo by The Doctor71 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/198978-ignition-wire-meltdown-74-xlh-and-hd-service-bulletin-659#post4376553)) \\
 {{:techtalk:ref:elec:74_xlh_wiring_meltdown_1_by_the_doctor71.jpg?direct&300|}} \\
-After pics. Back in the garage, with pics of the horn mounting bracket, et al, after removal. ((photo by The Doctor71 of the XLFORUM http://xlforum.net/forums/showthread.php?p=5805036#post5805036)) \\
+After pics. Back in the garage, with pics of the horn mounting bracket, et al, after removal. ((photo by The Doctor71 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/198978-ignition-wire-meltdown-74-xlh-and-hd-service-bulletin-659#post4376553)) \\
 {{:techtalk:ref:elec:74_xlh_wiring_meltdown_2_by_the_doctor71.jpg?direct&230|}} {{:techtalk:ref:elec:74_xlh_wiring_meltdown_3_by_the_doctor71.jpg?direct&230|}} {{:techtalk:ref:elec:74_xlh_wiring_meltdown_4_by_the_doctor71.jpg?direct&230|}}
@@ Line 72: / Line 66: @@
 {{:techtalk:ref:elec:74_xlh_wiring_meltdown_7_by_the_doctor71.jpg?direct&300|}} \\
+===== Hopper's 1977 XLCH =====
-====== Hopper's 1977 XLCH ======
+Or: Most carb problems are electrical. ((Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire?t=277021)) \\
-Or: Most carb problems are electrical. ((Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=277021)) \\
 Hopper had been fine tuning the Keihin carburetor to get a nice reliable idle without carb farts, stalling, or unwanted high-idling. \\
@@ Line 123: / Line 115: @@
 Oh well, just another day with the Ironhead. Gotta go and buy some heat shrink tubing. \\
+The bracket is rubber mounted. \\
+The part that broke was the top part that bolts to the big heavy bridge bolted between the two heads, and the rubber bobbin attaches to it. \\
+So the actual horn and small bracket are isolated from the vibes. \\
+It broke right where the thin (.080" or so) bracket stuck out past the heavy (3/8") bridge. \\
+The bracket is sort of roughly chromed so it looks like there was some hydrogen embrittlement from the chroming. \\
+That combined with HD vibration. Poor design that lets the bracket flex in use and the repeated heat cycles of the between the cylinder location. \\
+The break is crystalized and you can see it was broke 3/4 of the way through for a long time before. \\
+A TIG weld repair with gussets should work to stop future flexing, and a properly insulated ignition switch set up will stop it from happening again. \\
+See that broken horn bracket right where my finger is pointing in the pic below. \\
+And the bare terminals right below it. And the shiny copper wire direct from the battery, that used to have red insulation on it. \\
+Well toasted. Nothing to insulate those terminals if something goes wrong. \\
+In the third pic below is what fractured and fell down on top of those bare hot terminals. \\
+{{:techtalk:ref:elec:74_xlh_wiring_meltdown_1_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) {{:techtalk:ref:elec:74_xlh_wiring_meltdown_2_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) {{:techtalk:ref:elec:74_xlh_wiring_meltdown_3_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) \\
+This is all that was left of the main power wire from the battery to the ignition switch. \\
+A good foot of copper simply vaporized and disappeared. \\
+{{:techtalk:ref:elec:74_xlh_wiring_meltdown_4_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) \\
+Nearby wires were well fried too, the ones going to the breakers after they leave the switch in the first pic below. \\
+The others are the other end of the main loom going under the seat post area. \\
+{{:techtalk:ref:elec:74_xlh_wiring_meltdown_5_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) {{:techtalk:ref:elec:74_xlh_wiring_meltdown_6_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) {{:techtalk:ref:elec:74_xlh_wiring_meltdown_7_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) \\
+Took some fixing. \\
+I opened the melted outer cover, replaced the fully toasted wires, patched some singed ones with fusion tape and Nitto tape, heat shrink and whatever it took. \\
+Had to solder some new sections in some. \\
+{{:techtalk:ref:elec:74_xlh_wiring_meltdown_8_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) {{:techtalk:ref:elec:74_xlh_wiring_meltdown_9_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) \\
+The rat's nest under the seat survived unscathed except the wires to the ignition breaker and lights breaker. \\
+I added another fourth breaker, a 30amp job, right next to the battery so this cant happen again. \\
+The closeness of wires and terminals and steel frame and fender parts is absolutely terrifying. \\
+But I figure the master breaker right at the battery will prevent any meltdown if a bottle cap or something should blow in there off the road and arc those terminals. \\
+{{:techtalk:ref:elec:74_xlh_wiring_meltdown_10_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) {{:techtalk:ref:elec:74_xlh_wiring_meltdown_11_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) \\
+And the ignition switch now has a cocoon of fusion tape and Nitto tape to insulate those terminals plus some super heavy duty heat shrink to go over top off all that. \\
+Also the patched and spliced main loom with a couple of layers of Nitto tape wound around it in opposite directions. \\
+And the TIG welded horn bracket with a strengthened patch so hopefully it won`t break again. \\
+{{:techtalk:ref:elec:74_xlh_wiring_meltdown_12_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) {{:techtalk:ref:elec:74_xlh_wiring_meltdown_13_by_hopper.jpg?direct&300|}} ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/55696-my-bike-caught-fire/page4?t=277021&page=4)) \\
 \\

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