G1 blowing the main fuse - help with troubleshooting

[checkoutmyjunk]

I sold a cart to a cousin whom is also a neighbor, and that means an endless warranty!

The cart was flawless for the year or so I owned it, once I sold it, it started acting up and that is where I would like some help.

The starter generator looks to be an an aftermarket unit, and the voltage regulator was a very new looking aftermarket scamazon unit.

The main 10A fuse would pop after it ran, so as long as I kept feeding it the onions, the cart kept running. Once I let the engine stop spinning, no power to the relay/solenoids because the fuse blew thus no workie.

The battery was not charging either.

In summary: Aftermarket S/G + VR = blowing fuses after start up and not charging the battery.

I replaced the VR with a used OEM unit from the parts cart and it was charging again. I started and stopped it a few times and no fuses were blown.

I am not 100% this is the fix.

I took the after market VR apart and discovered that the spring that holds the NC contacts together had literally burned it's hook off. The contacts and coil looked fine. What would cause the tension spring in the VR to get so hot that it melted the end off?!?

[Lochlin]

Melted anything in electricals is normally the fault of a bad or dirty connection somewhere. Electricity wants to flow from the positive terminal of the battery to the negative terminal in the battery. When something prevents that flow from happening, the electricity must find some other way to dissipate and that could be anywhere else in the cart by way of heat production. In your case, it's likely that the VR was the easiest place for this to occur. Hence the melted spring.

You probably want to go through all the wiring on that cart to make sure that all connections are clean and tight with the understanding that where the electrical blockage is may not necessarily be close to the VR. A hint, dielectric grease is God's salve for all things electric. Not only does it help conductivity now, it also prevents dirty connections in the future.

[checkoutmyjunk]

Originally Posted by Lochlin

Melted anything in electricals is normally the fault of a bad or dirty connection somewhere. Electricity wants to flow from the positive terminal of the battery to the negative terminal in the battery. When something prevents that flow from happening, the electricity must find some other way to dissipate and that could be anywhere else in the cart by way of heat production. In your case, it's likely that the VR was the easiest place for this to occur. Hence the melted spring.

You probably want to go through all the wiring on that cart to make sure that all connections are clean and tight with the understanding that where the electrical blockage is may not necessarily be close to the VR. A hint, dielectric grease is God's salve for all things electric. Not only does it help conductivity now, it also prevents dirty connections in the future.

Thanks, I recently did this to the cart. I looked over all the connections under the clamshell. I admit that I skipped the ones for the ignition. When this problem first started happening, I was suspecting a short so I checked and cleaned all the connections points sans the ignition switch area.

The odd part is the spring in the VR is there for mechanical purposes, it is not there to conduct electricity. Am I wrong in my assessment of the VR? Have you ever opened one and looked at the internals?

[Lochlin]

There are multiple types of VRs. Most are solid state meaning that they are resin filled and you can't open it. There are a number of older styled ones that can be opened and adjusted. Yes, have been on the inside of some of those for adjusting purposes but never actually took one apart. Still, just about all of those components are China made now. It is what it is what that stuff. That spring could well have been out of place and touching stuff right out of the box.

[checkoutmyjunk]

Originally Posted by Lochlin

There are multiple types of VRs. Most are solid state meaning that they are resin filled and you can't open it. There are a number of older styled ones that can be opened and adjusted. Yes, have been on the inside of some of those for adjusting purposes but never actually took one apart. Still, just about all of those components are China made now. It is what it is what that stuff. That spring could well have been out of place and touching stuff right out of the box.

Thanks again, I am being a bit coy, I have an electronics education and worked in the industry for over a decade. I know a thing or two about electricity.

What I don't know is how that spring managed to get that hot. The contacts on a relay (effectively the same as part of the VR) are typically made of silver cadmium oxide, its used because it is tough and does not degrade quickly during the arcing as the contacts are made and broken. The a piece of mild steel for instance would weld under the kind of arcing a relay contact sees. I took the VR apart further and the contacts were not damaged. If I understood why that spring got so hot, I think I would know what actually failed.

[Lochlin]

Yeah, your electrical experience is a lot better than mine. I am a suit and day office guy who happens to have a lot of hillbilly in him. My hobby is to find broken carts and fix them up.

In looking at your pic, I don't know how that can be anything other than a defect. Nothing else makes sense.

[Cartmaster]

That spring appears to be directly connected to the moving contact, so may/must have been seeing voltage at some point. It would be interesting to compare it to an exact replacement to see where the bottom of the spring lands. My guess would be that maybe the same point it lands is also connected to power and a contact or connection went high resistance and all the power was flowing through the spring? Apart from it touching something else, its the only thing that makes sense to me to get that hot.

[checkoutmyjunk]

Originally Posted by Cartmaster

That spring appears to be directly connected to the moving contact, so may/must have been seeing voltage at some point. It would be interesting to compare it to an exact replacement to see where the bottom of the spring lands. My guess would be that maybe the same point it lands is also connected to power and a contact or connection went high resistance and all the power was flowing through the spring? Apart from it touching something else, its the only thing that makes sense to me to get that hot.

I think I figured it out, the S/G was hooked up backward and cooked the spring. The S/G wiring was corrected AFTER the spring was cooked leaving the VR contact closed and not limiting the current from the charging field on the S/G.

With the OEM VR, no problems have been reported after about an hour of run time.

Just a theory, wouldn't bet much on it being right just yet!

Thanks for the responses boys, if anything changes, I will update the thread.

[checkoutmyjunk]

Originally Posted by checkoutmyjunk

I think I figured it out, the S/G was hooked up backward and cooked the spring. The S/G wiring was corrected AFTER the spring was cooked leaving the VR contact closed and not limiting the current from the charging field on the S/G.

With the OEM VR, no problems have been reported after about an hour of run time.

Just a theory, wouldn't bet much on it being right just yet!

Thanks for the responses boys, if anything changes, I will update the thread.

I thought I would update the thread, the cart has performed flawlessly since and I am reasonably sure this was a self inflicted problem!