Check the battery connections and the ground path to frame.
Charge the battery.
Perform a load test.
Charge the battery.
Perform a load test.
CX500C Losing Electrical Power
So I've had this now 3 times over the last week. I would turn the ignition on, the oil & neutral lights come on, hit the start button, lights go out, & I have no power at all. I've checked fuses, battery connections, ground cable, etc. The 1st time after checking over everything, a couple hours after it happened, I turned the ignition on, had power back, hit the button, & fired it up. Last night I was out when it happened the 2nd time. Had to get it loaded, brought it home, turned the ignition on, had power again, but I didn't try to start it. Thought maybe it might be actually in the ignition switch. I had swapped out last year to a new switch so I had the old 1 to put in. Put the old (original) switch back in, turned on, had power, hit the switch, & dead. Gave up for the night. Checked this morning before work & it's still dead. Hopefully now if it stays that way it will make it easier to diagnose, but any thoughts or recommendations as to where to look? This is on a 1982 CX500 Custom. Thanks!
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As Randall stated, put a meter on the battery before hitting the button and while hitting the button/turning the key on.
Good point, thank you. I'll check that out tonight & report back.
This really sounds typical of a poor power connection somewhere that can pass enough current for the lights but fails as soon as the starter motor tries to pull more current through it. This is usually a loose battery cable but a cracked open link ("dogbone") main fuse can have similar symptoms. If it is the fuse it can look normal to the naked eye and even test OK if tested in place (meters draw very little current).
These fuses are prone to corrosion due to contact with the air for decades and have been known to turn to powder when touched. AFAIK replacements are still available from Honda but we usually recommend replacing it with a modern blade fuse in an inline fuse holder because in an emergency you can get a replacement anywhere.
These fuses are prone to corrosion due to contact with the air for decades and have been known to turn to powder when touched. AFAIK replacements are still available from Honda but we usually recommend replacing it with a modern blade fuse in an inline fuse holder because in an emergency you can get a replacement anywhere.
I replaced that dogbone fuse years ago with a blade fuse. I'll check all the main connections & report back. I relocated the battery about a year & a half ago to a box under the motor, so it is somewhat of a pain to get out & go over the connections.
It was just weird how I had this late last week, really didn't fix anything, then it worked fine for like 5 days.
Thanks for the input!
It was just weird how I had this late last week, really didn't fix anything, then it worked fine for like 5 days.
Thanks for the input!
Also check for corrosion (or dirt) on contacts: Starter Relay Switch, Rectifier, starter button. Dielectric grease is your friend on the contacts.
It may be your friend but dielectric grease is an insulator, is non-conductive. Apply to the connection after the connection is made.... Dielectric grease is your friend on the contacts.
Contact cleaner is your real friend ;-)
How old are the switches? They have corrosion?motofaction has an article on changing the lower part of the switch with a new one check and see if that would help you. I would definitely start my path with a download of the FSM and trace from there. Unplug the switch and inspect the connector and the harness, is it possible the headlight harness would be the problem.
A connector that doesn't displace the dielectric grease from between the mating surfaces won't be tight enough to maintain good contact.It may be your friend but dielectric grease is an insulator, is non-conductive. Apply to the connection after the connection is made.
I usually fill the female side before connecting.
We've been through this before. Dielectric grease is not a cure for dirty contacts and in some cases can even trap water inside connectors. If you must use it it is best to smear a tiny dab thinly on the prongs of the male part of the connector.
In any case it is far better to get the connections clean before you apply anything you hope will keep them from oxidizing.
In any case it is far better to get the connections clean before you apply anything you hope will keep them from oxidizing.
Another product I like using is "Corrosion X". It was made for the aerospace industry (Boeing) and is very popular with the marine industry in the Seattle area. More than one boat has been re-floated, wiring hosed down with Corrosion X and saved a lot of what would've been otherwise lost. The red can for general use, the blue can for undercarriage and suspension joints you want to keep rust free. Manual cleaning kind of goes without saying in my book.
So I got into it a bit last night. Definitely no blown fuses. What I was able to replicate is that when I do have power when I turn the ignition on, when I hit the start button, I hear the solenoid click, then I lose all electrical power. What I can't figure out yet, is how it "resets", still had no power when I turned the ignition on this morning. The battery does have over 12v, haven't checked it fully though. Is it possible the solenoid is bad & that's what's doing it? I've had solenoids go bad in the past on other things but not have the system act like this.
You have either a bad battery or a bad connection. Measure battery voltage with key in off position, with key in run position and with key in run position and start button pressed.
Disconnect and clean the two terminals on the battery, the terminals on the starter solenoid, the connection point on the starter and the ground connections.
Disconnect and clean the two terminals on the battery, the terminals on the starter solenoid, the connection point on the starter and the ground connections.
What voltage are you seeing at the battery when the start button is pressed? A battery can show 12v at rest and be dead under load.
What Mike said ^^^^^
A bad solenoid won't make all of the lights turn off. The only thing that will do that is for the system voltage to decrease below what is necessary to make them work and if they work until you press the Start button that means either the battery is not capable of producing the power that the starter motor needs or a connection somewhere is not good enough to pass the current the starter motor needs.
Old guy story: When we were in our 20s we had some friends over one day and when one of the guys tried to start his car it did exactly what you describe (although this was the first time so it didn't have a chance to show up as intermittent). Several of us were gathered around it with the hood up trying to offer suggestions (but none of us really had a clue) when another fellow's older brother arrived to pick him up. This guy took listened to the description (lights came on but everything died when he tried to start) and then reached in and wiggled the battery cables.
To the surprise of the rest of us one of them turned on the battery's post. He wiggled that one back & forth a few times to break any oxidation while telling us that this was one of the most common reasons for a car not starting, then sent me to fetch a wrench to tighten the clamp. After that the car started first try.
Since then I've come across a few examples of this happening, including at least one bike that was fine after the battery terminal bolts were loosened, the cables wiggled (to displace anything between the cable's lug and the battery post) and the bolts tightened again.
So what does all this mean to you? Measuring the voltage at the battery before & while pressing the Start button will tell you whether the problem is the battery or a connection but if I was stuck in a parking lot somewhere without a meter I'd look for a bad connection at the battery.
DISCLAIMER: Any time you put a wrench on the positive battery bolt while the negative is connected be VERY careful not to let it touch anything grounded. And if you wear a ring don't let it touch ground while you are holding that wrench (google electrothermal ring burn).
A bad solenoid won't make all of the lights turn off. The only thing that will do that is for the system voltage to decrease below what is necessary to make them work and if they work until you press the Start button that means either the battery is not capable of producing the power that the starter motor needs or a connection somewhere is not good enough to pass the current the starter motor needs.
Old guy story: When we were in our 20s we had some friends over one day and when one of the guys tried to start his car it did exactly what you describe (although this was the first time so it didn't have a chance to show up as intermittent). Several of us were gathered around it with the hood up trying to offer suggestions (but none of us really had a clue) when another fellow's older brother arrived to pick him up. This guy took listened to the description (lights came on but everything died when he tried to start) and then reached in and wiggled the battery cables.
To the surprise of the rest of us one of them turned on the battery's post. He wiggled that one back & forth a few times to break any oxidation while telling us that this was one of the most common reasons for a car not starting, then sent me to fetch a wrench to tighten the clamp. After that the car started first try.
Since then I've come across a few examples of this happening, including at least one bike that was fine after the battery terminal bolts were loosened, the cables wiggled (to displace anything between the cable's lug and the battery post) and the bolts tightened again.
So what does all this mean to you? Measuring the voltage at the battery before & while pressing the Start button will tell you whether the problem is the battery or a connection but if I was stuck in a parking lot somewhere without a meter I'd look for a bad connection at the battery.
DISCLAIMER: Any time you put a wrench on the positive battery bolt while the negative is connected be VERY careful not to let it touch anything grounded. And if you wear a ring don't let it touch ground while you are holding that wrench (google electrothermal ring burn).
Thank you guys for your excellent advice. I'll have to check more tonight. Now that I have the battery box out from under the engine, I can check it more closely.
I didn't say it, but I always clean the contacts first.We've been through this before. Dielectric grease is not a cure for dirty contacts and in some cases can even trap water inside connectors.
I completely forgot. I had this exact same issue with my truck last fall! Ended up being a loose battery connection.What Mike said ^^^^^
A bad solenoid won't make all of the lights turn off. The only thing that will do that is for the system voltage to decrease below what is necessary to make them work and if they work until you press the Start button that means either the battery is not capable of producing the power that the starter motor needs or a connection somewhere is not good enough to pass the current the starter motor needs.
Old guy story: When we were in our 20s we had some friends over one day and when one of the guys tried to start his car it did exactly what you describe (although this was the first time so it didn't have a chance to show up as intermittent). Several of us were gathered around it with the hood up trying to offer suggestions (but none of us really had a clue) when another fellow's older brother arrived to pick him up. This guy took listened to the description (lights came on but everything died when he tried to start) and then reached in and wiggled the battery cables.
To the surprise of the rest of us one of them turned on the battery's post. He wiggled that one back & forth a few times to break any oxidation while telling us that this was one of the most common reasons for a car not starting, then sent me to fetch a wrench to tighten the clamp. After that the car started first try.
Since then I've come across a few examples of this happening, including at least one bike that was fine after the battery terminal bolts were loosened, the cables wiggled (to displace anything between the cable's lug and the battery post) and the bolts tightened again.
So what does all this mean to you? Measuring the voltage at the battery before & while pressing the Start button will tell you whether the problem is the battery or a connection but if I was stuck in a parking lot somewhere without a meter I'd look for a bad connection at the battery.
DISCLAIMER: Any time you put a wrench on the positive battery bolt while the negative is connected be VERY careful not to let it touch anything grounded. And if you wear a ring don't let it touch ground while you are holding that wrench (google electrothermal ring burn).
1 - 20 of 21 Posts
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