Voltage Regulator?

Sawdust

Jim from Kentucky
Staff member
Moderator
Member
Can a faulty VR cause a closed circuit through a key switch or starter solenoid to the point where when the battery is connected the starter generator starts turning with the key off. This is on a Sears SS15 with a Briggs. I previously had an erratic charging problem. I took all the connections on the S/G, VR, Solenoid, Ammeter, and Key Switch to clean. Once I hooked everything back up as soon as the battery was connected the S/G started spinning. While it was spinning I turned the key to the start position and I could here the solenoid click as it should when working properly. I took the key switch and solenoid back off to bench test for continuity. None through the large solenoid terminals but there was when the wires were connected which tells me something is allowing the voltage to pass through the solenoid to the S/G, none on the key switch until I turned it to the start position. I took pictures and checked that everything was wired back up the same way. Any help is appreciated, thanks.
 
Sounds like a contact in the regulator is stuck... contact points stuck together. Had this happen myself.
That’s the only thing I can think of. I had it apart also and cleaned the points but didn’t look like they were too bad. I’m going to take it out again tomorrow and check that.
 
That’s the only thing I can think of. I had it apart also and cleaned the points but didn’t look like they were too bad. I’m going to take it out again tomorrow and check that.
Look closely at the bottom of each coil tower inside the regulator. Been many years, but twice I found a wire running from one coil to the other close to bottom of case that burned in two. It caused weird things to happen. I soldered a bridge to connect them and all went to normal. I can't remember between what coils it did this, and easy not to notice.
 
I’m interested what’s the trouble Jim. Let us know what you find. Almost sound like the solenoid. But you’ve tested that. The start wire from the solenoid to the starter generator is not touching power some where is it. ?

Noel
 
I’m interested what’s the trouble Jim. Let us know what you find. Almost sound like the solenoid. But you’ve tested that. The start wire from the solenoid to the starter generator is not touching power some where is it. ?

Noel
 
I took the VR off today and it looks fine, I switched out to a known good key switch, tapped on the solenoid and still same problem. I don’t understand why voltage is going through the solenoid but taking the battery wire and S/G wire off there is no continuity through the solenoid. I don’t have any spare VR so tomorrow I might take a donor off of another tractor and see what happens.
 
One thing I didn’t understand taking this apart was why the red wire from the ammeter was piggybacked on top of the brown wire going to the S/G on the same VR connector.
1948142A-FDE0-40C2-B029-D57C1C780D77.jpeg

I got a PM from Stew ( 29 Chevy) from another forum with a lot of technical advise with a description on how these VR work. I understand now why most of us just replace them. Mine had a connector under the VR that was not being used. I was told this is where the brown wire should be connected. I made the changes and now everything works as it should with one exception, it’s charging the battery around 15-16.8 volts using my volt meter at the battery. My ammeter is showing the normal 10-14 volts. I know these can be adjusted so that is what’s on today’s agenda.
3AD3B995-C42B-45AE-B915-F13AE4314C21.jpeg
 
I haven't got a manual for an SS/15 but looked at one for the Suburban 15 and it shows the brown wire going to that middle post. The one under is a ground back to the engine. Not sure what the difference is. Here's that manual if needed. I also have a service manual for these VR's.
 

Attachments

  • 91725200.pdf
    4.4 MB · Views: 1
Back
Top