[nickv99]

Hello All,

I have an odd ball issue as of late on my 1980 448. I was blowing snow and having zero issues and then all of a sudden the tractor seemed to be running strange. I throttled down and all seemed fine so I throttled back up and said yep something is wrong. I attempted to shut the key off but the tractor kept running. I finally choked it to stall it out and then tried a restart, nothing dead as a door nail. The main fuse was blown so naturally I tried a new one and it also blew. Time to investigate.

First I did some preliminary checks of the wiring no rub through in fact it's all brand new. Tested the coil, checked points, and everything checked out. So I moved on to the Stator and regulator. I unplugged the regulator and it fires right up and does not blow the fuse at this point. Check stator voltage and it was over 40 at wide open so that's all good. I plugged the regulator back in after cleaning it and it's grounds and as soon as the key was at run the fuse blew again. One thing I noticed was the regulator was hot to the touch at that point. So my theory is the regulator is bad but can't get it to not blow the fuse long enough to fire the machine up and check output voltage.

Thoughts?

Thank you,

Nick

 

[bhildret]

Agree, almost certainly the regulator is bad.

There are conditions in the rectifier bridge that can result in unregulated voltage (charging at 16+ measured DC, intermittent or hard fail) or diode shorts to ground.

C31249 is the correct replacement for that era 448:

C31249 } RECTIFIER

RECTIFIER KIT

salempwr.com

Brian

 

[nickv99]

Brian,

Thank you for chiming in I feel like I'm heading in the right direction now. Just wanted to make sure I wasn't going crazy.

I ordered a regulator from you the other day in anticipation that was what it would be I forgot to add that part. I ordered it from you but went with the kit form. Hopefully this is the right one?

C43910 } KIT REGULATOR/RECTIFIER

 

[bhildret]

Yes, that kit should work also. That includes a C31249 and some additional electrical bits with instruction sheet.

Brian

 

[Ray_McAvoy]

I agree with Brian that it's most likely the regulator.

But just to be on the safe side, you might want to check to make sure the stator doesn't have a short to ground.

I believe it's possible for a stator to still generate it's normal amount of AC voltage between it's two wires (when unplugged from the regulator) even if it has a short to ground. However, when plugged back in, it would blow the fuse.

 

[nickv99]

Man I sure hope your wrong in a sense ha ha! If the stator is gone we all know what that means out comes the engine. I took my multi meter and ohm checked it to the frame on both leads and the results fell within spec. We'll see what happens when the new regulator shows up.

 

[Ray_McAvoy]

Yeah, hopefully it's not the stator. If you got an open circuit reading (which is spec for the stator short to ground test) when measuring from the engine / frame (ground) to each of the stator leads, you should be all set.

And even if you did get a reading that would indicate a stator shorted to ground, it would be worth taking a close look at the insulation on the stator lead wires to see if there might be a spot thats worn / chafed and shorting to ground. Something like that would be easier to fix than having to replace the stator itself.

 

[myerslawnandgarden]

Anytime the engine continues to run with the key off, it is an indicator that the bridge is gone in the voltage regulator. You are on the right track, just replace it.

C31249 Voltage Regulator/Rectifier Single Bolt (casegardentractorparts.com)

Bob

 

[nickv99]

Bob,

You just gave me another feeling of positivity that I have this narrowed down. Hopefully we'll find out this weekend sometime once my parts arrive. I also order from you too Bob. I try to spread the love to all dealers when I can.

Thanks,

Nick

 

[nickv99]

Good evening all,

Since I know how much I hate when a thread goes without a follow up here's mine. I received my new regulator promptly from Brian and got it installed and all is well again. Charging perfectly and running great. Had to miss out on the latest snowfall but ready for the next.

Thank you to all that chimed in it was much appreciated.

Thanks,

Nick