M-18 Kohler rectifier/regulator??
 

Hello everyone, got another question.

have a m18 in an 81 782. all the sudden it started blowing the 10 fuse to the PTO. i noticed that the ammeter was reading high. some times when i turn the lights on the tractor on or turn the PTO on it comes down. also i can control how high the needle climbs with the when i increase the engine rpm. (speed up engine, ammeter reads charging more. slow engine speed, ammeter runs lower). other times the ammeter just stays reading high but doesn't fluctuate. i check the voltage and it stays a continuous 15 . I've been checking every for possible shorts but cant find any. when i check the hot wire coming of the regulator and it also was 15. i was able to mow using a 15 amp fuse, but i don't want to do that because I'm scared i will burn up my PTO.

my question is, do you guys think it is my regulator/rectifier?

Sounds like maybe the regulator is failing or stuck... Either way, I think you should replace it. But, before you do, check something. You say that you get a reading of 15. I am going to assume 15 volts, but where? At the battery? If so, yes it is OVER charging and needs fixed. The max I like to see on a 12V system is about 14.6. Different people would give a number close to that one. But either way I think we would all agree 15 is too much.

If, the reading you are getting is NOT at the battery, check the ignition switch and the fuse holder. I have seen a poor connection at either point cause the voltage regulator to "think" it was trying to charge a weak battery, when in fact it just wasn't getting signal to reduce voltage. With the motor running at about half throttle, reach in and wiggle the plug on the back of the key switch and see if the ammeter drops. Do the same at the fuse holder. If either feel hot to the touch, that is also a good indication of a poor connection.

Good luck!:beerchug:

yes, it reads 15 volts across the battery when the motor is running and 12 when the motor is off.

It is imperative, that the V/R is properly ground. With a DVM or VOM, check to see if you have zero ohms resistance between the Battery Negative Terminal and the V/R case (or housing).

im guessing that the "v/r" is what im calling the regulator/rectifier. and to check between the v/r casing and the negative battery terminal (which im guessing is the negative battery post) the engine should be running?

so "ohms", which my meter has, is a real way to check for ground? i just wiggle wires and watch the volt ameter which cant be very accurate or other bsevable changes such as lights dimming. what should the ohms read?

guys please excuse me, im not very good with electrical and i justwant to make sure im on the same page. and also, thanks for your help.

NO...

Perform the test as previously stated and advise.

just measured from negative terminal to the regulator housing and the meter reads 0 ohms.

Then, I would replace the V/R.

replaced the regulator over the weekend and the tractor is running like a charm. needle staying at 0. thanks for your help