What Is This Noise? (electrical question)

[brabnadon]

Hello! I’m working on a project XS500, the ‘78, and I’ve got a parasitic drawl in my electrical system somewhere. When you crank the key, the battery drops around 3volts and continues to drop down. On a new battery, she won’t even crank. When you jump the battery and start it, she’s been trying to crank, but the sound has started to change as she refuses to crank, there’s a buzz/beep in the electrical system somewhere. (Video of Sound.) Tomorrow, I'm going to check the stator coil as well as the starter, but would anyone have any ideas on what to check?

 

[Raymond]

Well, Hi @brabnadon and welcome to the forum. Problems with the electric start are well-known and for that reason, I always kick my bike into life. That's not much help to you, I know, but people will be along and suggest things you can check. The most frequent problemo with the starter circuit is a weak engagement spring, which can be fixed. Cheers, Raymond

PS Just noticed the bike is an XS500 so ignore what I said - don't know much about the 500s and their problems are likely to be different.

 

[Downeaster]

Sounds to me like the solenoid is chattering. A bad solenoid (either mechanically or electrically) won't conduct sufficient current to spin the starter.

As a troubleshooting step, try connecting a good, heavy set of jumpers directly to the post on the starter (with the negative lead to ground of course...)

Another possibility is bad cables. That's not always detectable visually, as corrosion or breaks can happen under the insulation. Low current TO the solenoid can cause that chatter as well.

 

[brabnadon]

Well, Hi @brabnadon and welcome to the forum. Problems with the electric start are well-known and for that reason, I always kick my bike into life. That's not much help to you, I know, but people will be along and suggest things you can check. The most frequent problemo with the starter circuit is a weak engagement spring, which can be fixed. Cheers, Raymond

PS Just noticed the bike is an XS500 so ignore what I said - don't know much about the 500s and their problems are likely to be different.

Thanks for the warm welcome
I appreciate the help still. I know there are some similarities between the two bikes so I’ll do some digging to see what’s up.

 

[brabnadon]

Sounds to me like the solenoid is chattering. A bad solenoid (either mechanically or electrically) won't conduct sufficient current to spin the starter.

As a troubleshooting step, try connecting a good, heavy set of jumpers directly to the post on the starter (with the negative lead to ground of course...)

Another possibility is bad cables. That's not always detectable visually, as corrosion or breaks can happen under the insulation. Low current TO the solenoid can cause that chatter as well.

I hear you. I’ll get in there and check, hopefully find the fix. I’ll update this post later after working.

 

[Lou_TX]

Howdy from Texas and welcome to the club!
I agree with Downeaster that it sounds like (pun intended) a relay. Plenty of "safety" and other relays on these bikes.
In your case, I would also recommend to try the starter directly powered by the battery via its primary cable or jumper cables and work your way backward.
This might sound like a lot of work but you want to check all connections and all wires first to ensure proper flow of electricity. If amps can't travel, things don't work well. Good grounds, good connections, tight connections.
Do you have a wiring diagram for the bike yet? And are you good with electrical?

 

[brabnadon]

Howdy from Texas and welcome to the club!
I agree with Downeaster that it sounds like (pun intended) a relay. Plenty of "safety" and other relays on these bikes.
In your case, I would also recommend to try the starter directly powered by the battery via its primary cable or jumper cables and work your way backward.
This might sound like a lot of work but you want to check all connections and all wires first to ensure proper flow of electricity. If amps can't travel, things don't work well. Good grounds, good connections, tight connections.
Do you have a wiring diagram for the bike yet? And are you good with electrical?

I’ve got myself a pretty solid diagram, all the work ive been doing has been over by my finger. I have a basic understanding of electrical work, however I hate it with every living ounce of my body LOL! I will be very active in here until I can get the electrical problems out of the way.

 

[brabnadon]

Hello! I’m working on a project XS500, the ‘78, and I’ve got a parasitic drawl in my electrical system somewhere. When you crank the key, the battery drops around 3volts and continues to drop down. On a new battery, she won’t even crank. When you jump the battery and start it, she’s been trying to crank, but the sound has started to change as she refuses to crank, there’s a buzz/beep in the electrical system somewhere. (Video of Sound.) Tomorrow, I'm going to check the stator coil as well as the starter, but would anyone have any ideas on what to check?

As an update for today, I’ve tested the solonoid (or as my diagram calls it, the stator switch) which seemed to have both power in and out of it, so I’m assuming it’s good. While my next step will likely be checking the starter as many of you have said, I still have speculations of other issues:

I come from a history of car restorations, and my old ‘76 f100 had a very similar issue. After months of trial and error, A loose ground on a fusible link wound up pulling all of the power. That being said, there’s some fairly sketchy wiring work coming out of the solonoid, as well as a rectifier that’s seen some age. Any idea if that could be what’s stripping the power from the circuit?

 

[Its been a long time]

As an update for today, I’ve tested the solonoid (or as my diagram calls it, the stator switch) which seemed to have both power in and out of it, so I’m assuming it’s good. While my next step will likely be checking the starter as many of you have said, I still have speculations of other issues:

I come from a history of car restorations, and my old ‘76 f100 had a very similar issue. After months of trial and error, A loose ground on a fusible link wound up pulling all of the power. That being said, there’s some fairly sketchy wiring work coming out of the solonoid, as well as a rectifier that’s seen some age. Any idea if that could be what’s stripping the power from the circuit?

The XS500 has a separate rectifier like the XS650? You can quite easily check the rectifier with a multimeter. Mine checked out OK but I decided to replace it with one of the generic rectifiers off eBay. They're very cheap and easy to replace. I took that route because then I knew it was good, no question.

 

[brabnadon]

The XS500 has a separate rectifier like the XS650? You can quite easily check the rectifier with a multimeter. Mine checked out OK but I decided to replace it with one of the generic rectifiers off eBay. They're very cheap and easy to replace. I took that route because then I knew it was good, no question.

I hear you, likely will do that just for piece of mind, pretty sure my solonoid has been replaced at some point in time anyways.