Cadet 1641 charging/voltage regulator help

[cnysabo]

Hi guys-
I just went and read through all the 6 pages of posts to try and understand what has happened to this point. Having just replaced the regulator on my 1641, I was so glad to finally get the system charging at 14V again!
Anyway, not to be master of the obvious but I am wondering about that potentially blown fuse you mentioned? I know exactly which one you are talking about and I am wondering if you jump straight from the regulator to the positive battery terminal, wouldn't you bypass the fuse and therefore get an accurate reading of whatever voltage is coming back to to the battery?
In other words, it allows you to bypass the return to the ignition switch and the fuse and even a potential short from the R/R to the battery, but you still have the same voltage at the battery with the tractor off or on then it must be the regulator again... right?!
Forget all that if you have already tested that.
The other thing I just wanted to say from my experience is put the battery on a maintainer/charger and then see if it brings it up to 12 Volts again since there is a question about a possible bad cell. I mowed my yard (1 1/2 acres) on just the battery twice this year before I finally was able to get a regulator. After each mowing I had to charge it back up with a charger. I know it is not good for the battery to do this too often, but the owner of NAPA told said it wouldn't hurt once or twice.Not trying to add to the murkiness, but just trying to help you get your lawn mowed while you trouble shoot the real problem.

[cnysabo]

Sorry, I see you tested that fuse even though you couldn't get it out and it had continuity...

[Jbo_c]

I did. Thanks for trying. I also did the jump thing.

I am going to put the battery on a charger and make sure I can get it up to a full charge or confirm that it has a dead cell.

Jbo

[Jbo_c]

Still no luck. And everybody seems to be out of ideas. So here's a summary. Tell me what I've missed.

1. Swapped to a known good battery, so that's ruled out.
2. Tested the leads from the stator. 29.5 volts AC at full throttle. That rules out the stator.
3. Tested the same leads on the rectifier side of the connector. That rules out a bad connector.
4. Tested the red lead from the key switch to the rectifier. No voltage with the key off. Battery voltage with the key on and the engine off. That tells me there is definitely no broken wire or fuse problem between the battery and the rectifier. Also used a jumper wire from the battery positive to the red lead on the rectifier just for good measure.
5. Made sure the mounting point for the rectifier is clean for a good ground. Also used a jumper wire from the battery negative to the rectifier housing just for good measure.
6. The rectifier being used is a new Stens brand item. (second one after returning the first thinking I'd gotten a bad one).

All of this and still get only battery voltage measured at the rectifier with the engine running WOT.

Seems to me to point to a bad rectifier(still). But surely not.

I think I've covered all the things to check that have been generously suggested in this thread. I'd love for somebody to tell me what I've missed or if one of my assumptions about something being "ruled out" is wrong.

Thanks for the support.

Jbo

[ol'George]

Originally Posted by Jbo_c

Still no luck. And everybody seems to be out of ideas. So here's a summary. Tell me what I've missed.

1. Swapped to a known good battery, so that's ruled out.
2. Tested the leads from the stator. 29.5 volts AC at full throttle. That rules out the stator.
3. Tested the same leads on the rectifier side of the connector. That rules out a bad connector.
4. Tested the red lead from the key switch to the rectifier. No voltage with the key off. Battery voltage with the key on and the engine off. That tells me there is definitely no broken wire or fuse problem between the battery and the rectifier. Also used a jumper wire from the battery positive to the red lead on the rectifier just for good measure.
5. Made sure the mounting point for the rectifier is clean for a good ground. Also used a jumper wire from the battery negative to the rectifier housing just for good measure.
6. The rectifier being used is a new Stens brand item. (second one after returning the first thinking I'd gotten a bad one).

All of this and still get only battery voltage measured at the rectifier with the engine running WOT.

Seems to me to point to a bad rectifier(still). But surely not.

I think I've covered all the things to check that have been generously suggested in this thread. I'd love for somebody to tell me what I've missed or if one of my assumptions about something being "ruled out" is wrong.

Thanks for the support.

Jbo

I'm about to suggest trying a known good regulator as it seems to be leading in that direction.
if you have AC going in the rect/reg, it has to put DC out or it is a malfunctioning unit.
it is just hard to believe that 2 replacements,as well as original are defective.
Another option is put your original, or the new replacement, on a good working mower and see if it functions correctly.

[Jbo_c]

I'm with you OG. But I don't know where to get a known good regulator. I've asked everybody I know and can't find a known good one. Found a few potentially good, but none known good.

Jbo

[J-Mech]

Do you have any other engines around? Nevermind the brand.... You can use just about any on that system and it will work. But, I wouldn't borrow one. Just in case you have some weird short that is killing the system.


So... This is my suggestion. Start the tractor. Disconnect the positive battery cable from the battery after you get it running. Then, use the jumper wire to run from the Pos battery post to the output of the R/R. Maybe you have some odd short that is shutting the V-Reg off.

Another thing that is possible. The stator could be leaking A/C current into the ground side of the system and shutting down (or possibly even frying) the R/R. It wouldn't take many amps (less than an amp) to shut it down. However, when this happens it generally screws with the ignition. You may not be able to even test for it, as it would be hard to find, and may not register.

Did you ever do the test George suggested? Testing to see if the A/C voltage was falling off when the system tried to charge? You would have to back probe the two wires while everything was plugged in to test that. Did you do that??

[Berwil]

Where did you get the 2 new regulators? Maybe there was a bad run, or the last guy to return them defective fried them first. I would try a different supplier for a 3rd regulator.

Bill

[Jbo_c]

I did try the test OG suggested. No change.

No parts motors laying around. I do have a JD318 but I don't know how to determine if I can use that regulator without damaging my system. I'd sure hate to fry something.

I checked the stator leads and have infinite resistance to the frame.

Will try your idea about disconnecting the battery this evening if I have time.

Thanks for the feedback.

Jbo

[Jbo_c]

Started to do the test removing the battery positive and jumping but it doesn't run without the battery positive connected. Maybe I should be embarrassed to say but I was in a hurry and didn't think to place the jumper first, so didn't really test it. Will give it a go tonight.

Jbo