QuestionQUESTION: Hi Mr Silver...I searched the answers + see this addressed. Ive had my 1985 Honda Sabre VF700S for a year now without a problem. I replaced the battery 2 months ago. My bike just shut off while idling at a red light, 2 weeks ago. I pushed the start button with no sounds, just the headlight dims.
My battery is good. I suspected + replaced the kill switch/starter button assembly +wiring harness. I pushed the start button with same exact results. I directly connected the starter + the stater turns the engine but doesnt start. I now swapped out the relay with a 1981 750f relay. No change. Any suggestions on what to check next?
ANSWER: Mark, if your charging system is failing, the battery won't be able to keep up with the electrical load. The ignition is solid-state, so at a certain battery voltage the system shuts down. If you have changed out the control switch and starter solenoid/relay then you have to go back to the battery first, then the charging system once the bike is running again.
There are other components in the ignition system, which need to be checked and tested. There are igniters which control each coil, as well as the pulse generators which serve up timing signals to the ignition module.
There are fuses in the system and a main fuse on the starter solenoid/relay, so all those must be checked for full function. Fuses have been known to fatigue and crack instead of just blowing open due to a short circuit, so inspect them carefully with an ohm meter or with a 12v test light when the ignition switch is turned ON. Check the ignition switch base, itself as they have been known to separate partially, causing a loss of power to certain functions.
Find a shop manual or a wiring diagram on various internet forums, to help guide your troubleshooting. Fully charge the battery before you continue further. Depending upon how many miles you have on the bike, the charging system components may need attention.
Go to www.electrosport.com to find charging system troubleshooting charts and replacement components.
Bill Silver
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85 Honda Sabre
85 Honda Sabre
QUESTION: Mr Silver Thank you for your detailed attention. So I checked my battery + its giving out 12volts..but I charged it anyway just to be sure..+ it still shows 12 volts. I checked (continuity-connection test with the ohmmeter)at the 30 amp fuse at the relay and the smaller fuses..they all are fine.
The ignition switch looks intact...but Im not sure what Im looking for. There is a partially bent metal tab or bracket (1/4inchwide X 1 inch long) stemming out from the ignition base surrounded in a clear plastic cover. see photo attached, Could this be a ground connector? I cant find any loose wires nearby.
I have a wiring diagram for the 1981 Honda 750F. I checked electrosport + couldnt find a wiring diagram for my Sabre.
I then wanted to confirm the starter button (the one I replaced) was working. I see at the relay a red+yellow wire (see photo attached) that goes to the starter button, then back out splitting into about 8 other wires going to multifunctions. All these wires have continuity from the red/yellow wire at the relay only when the starter button is pushed. I believe the starter button is working.
I can swap out parts from the 750F. Im not sure what to check next. Should I suspect the relay and try a 3rd relay? Should I check the starter coils or the spark plugs for spark? I get no volts at the starter wire when I push the starter button. Thank you in advance.
V45 starting diagram
ANSWER: Mark, troubleshooting electrical problems really requires a proper wiring diagram and a good 12v test light. There are safety switches in the system which prevent the starter motor from engaging when the bike is in gear or the clutch is not disengaged.
http://www.openaspdf.com/files/3070653/83-85_VF750F-VF700F_Shop_Manual.pdf
See attachment for wiring drawing from that manual download.
Bill Silver
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85 Sabre wire pg1 
85 Sabre wire pg2
QUESTION: I found an 85 700s Sabre wiring diagram and have been painstakingly making notes. Im again trying to get my bike back on the road.
So my 1985 Honda Sabre 700s just stopped on me + the starter button didnt turn over the starter (8months ago). Ive replaced the starter/kill switch assembly + wires. Ive checked the fuses, including the starter solenoid 30amp. I switched the starter solenoid out with another Honda + it works fine.
So NOW I noticed the 10amp fuses keeps blowing for fuse#5 (starter/igniton fuse). This will only blow when I turn the kill switch on. If the kill switch is off the starter button will turn over the starter. (Maybe it was fine before because I possibly kept the kill switch off all this time). I see the black and white wire coming out of the kill switch and leading to my spark coil. I unplug the black and white wire from the coil and the wire shows continuity to ground (grounded)..even thought the ignition is off or on. Do you think I need to fix or replace the starter/kill switch assembly again? What else is left to check?
AnswerFrom your notes I would say to isolate the wiring for the kill switch from the coils at first. You have already changed out this switch, hopefully with a good used or new one, so the problem is probably downstream.
The kill switch wiring has a switched HOT (12v) black wire feeding the contact on one side and the other contact with the black/white stripe wires is headed for the ignition coils and spark units. Unplug each coil and see if that isolates the short to ground. Check the wiring harness and individual wires going to ignition system components to see if any are pinched and shorted out. Check the coil primary winding resistance to see if they match specifications and each other. If you don't find anything there, disconnect the two spark units, which run the ignition controls for each coil. These are known to fail and could well be your problem area. Disconnect them both, then plug each one in one at a time. Look at them for signs of overheating as they tend to drool gooey black stuff when they are dying.
The black/white wire goes to coils and to the spark units, so checking one black/white lead is bound to show continuity through the attached components. Disconnect all the black/white connectors and check from the kill switch back towards each component. Use an ohm meter to measure actual resistance values and when you find one towards ZERO, that is probably your failed component.
Bill Silver
