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1872 ELECTRICAL PROBLEM---- - HELP

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gsenterfitt

New member
Joined
Jul 14, 2007
Messages
4
displayname
Geary Senterfitt
I am new here and saw a post from July of this year-07.
My neighbor had a 1989 Cub Cadet 1872 with only 523 hours and rear PTO and lift. He became ill and passed away this past Febuary. He had always liked my two John Deere 430's and I had been mowing his two acres since his illness-at no charge. He had told me his 1872 had a blown hydraulic transmission. It had been parked under an outside shed since 1991. His wife and son gave me the 1872 after his death and said he wanted me to have it. This past summer I took it next door to my garage and draind and cleaned the tank and got it running. The carb was not correct. I purchased a new carb for it and it ran fine. I then found a broken hydraulic hose and purched another hose. It all seemed to work fine. I then repainted it and re did all the Saban 60 deck before painting it as well. Last month I started it and the wiring harness behind the key switch started smoking and the key switch would no longer turn. I replaced the key switch and paid close attention to the wiring and key switch. It cranks fine but the wiring still gets hot and I have to turn it off before it would fry itself or anything. I got my VOLT OHM meter and went to work. I found a white wire that leaves the key switch and reads to ground. I then did a search and the 1872 factory prints I have found do not list every componet,especially the rectifier in the circuit I found. The white wire goes to a rectifier and then two wires go to the alternator. I unplugged the regulator and the problem ground cleared at the key switch. I was thinking it was the regulator but then I tested both leads to the alternator and both of these two leads each read zero resistance to ground. I then did a search on the Cub Cadet site and found a drawing that looks basically the same as for my 1872. Is this correct? Can you provide information or input concerning my problem and is there a history of this type problem? Any input or information, especially a detaIed drawing of a 1872 that shows all PTO's, regulator,reverse switch,etc in detail would be greatly appreciated along with any input or where I should ALSO CHECK. I AM IN HOPES THIS INFORMATION WILL HELP SOMEONE KNOWLEDGABLE OF THIS PROBLEM. My diret email is [email protected] in case I do not get the navigation of this post results down. I am very new to this site, altho I am registered as gsenterfitt. Respectfully, Geary Senterfitt
 
Geary:

First, welcome to the Forum....
71319.jpg


Here is a Ignition Switch Diagram..
71320.jpg


The White wire is a feed from the Alternator/Regulator circuit, that keeps the battery charged.
The Red wire goes to the start circuit
The Black wire is the Battery feed to the whole system.
The Blue wire is the circuit for the lites.
The Yellow wire goes to the Magneto and kills the motor when in the off position.

If the White wire gets hot then it sounds like it is going to ground somewhere.

I assume you have the correct Ignition Switch and that it is wired correctly.

Please advise on further information.
 
Roland, Thanks for the descriptive explination. I have this drawing but can not find a Cub factory drawing that shows the rectifier in the any electrical circuit for a 1872. I made sure that I had the correct switch when I ordered it from the local dealer. In fact, I gave them the part numbers from my drawings and they double checked my numbers and came up with the same. One thing that threw me at first when I installed the switch was that I was holding it in my hand and it would not start the enging untill I looked at the block diagram AT THE BOTTOM OFF MY DRAWING AND NOTED THE SWITCH HOUSING WAS THE GROUND and I was holding it in my hand in order to test it before I put it in the dash. Once I secured the new switch it cranked up instantly......but the wiring got real hot and I shut it down instantly. The lights work, the PTO works, no reading to ground and all work properly when the white wire is removewd from my circuit!!. I have three manuals on this tractor and not one of them has a have the same exact "generic" drawings. I down loaded over 160 pages of a TECHNICAL MANUAL and it also does not have a drawing that includes the rectifier in the electrical circuit. Has any one else had this problem. Will I have to remove the engine to replace the alternator? Is there a chance the alternator can be repaired? I( guess it all depends. It seems to me if I replace the alternator I will also have to replace the rectifier? Remember the two leads that leave the rectifier both have zero resistance to ground. Thanks for your input, it is greatly appreciated.
Geary Senterfitt
 
Geary:

The Ignition Switch does NOT have to be grounded to start the Cub. It ONLY has to be grounded to stop the motor.

The 1872 has a Kohler M-18 motor in it. It has this charging system in it...

71327.jpg


The White Wire is connected to the B+ or middle terminal of the Rectifier/Regulator. If you have a maximum of 14.7VDC from the White Wire to ground when the motor is at WOT or 3600RPM, then all is well with the Charging System.

The Stator Coil is under the Flywheel of the motor.
The Rectifier/Regulator is under the Fan shroud.
 
Roland, Geary S: The wiring diagram for the 1872 engine is found in the Kohler Magnum M-18 & M-20 Sevice Manual and it clearly shows the
regulator/rectifier... Please look again....Try pages 8.6 thru 8.10. Note that the Cub Cadet wiring diagram shows where the regulator/rectifier connects to the Cub Cadet wiring harness... it is labeled "M 18 engine or M 20 engine".

Myron B
 
Only 1 wire diff. Odd the 15amp has a fuse and 25amp doesn't.
 
Myron:

I was fully aware of the Wiring Diagrams for the 1872 and where to find them. I have several copies and resources for same.

The Charging System is a 15 Amp system used both on the 1872 and 2072. It is also the same system used on the Q/L and 82 Series Cubs with Kohlers.
 
Problem solved----------Stator was shorted to ground on both leads. Removed engine and replaced stator and regulator. Problem solved with 70.00 and a days labor. Thanks guys,
respectfully,
Geary S.
[email protected]
 
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