I have a Cub Cadet LT1050 w/26 hp Kohler Command engine and I'm having issues with the electrical system. The battery won't stay charged up when I mow. The battery is new. I took some measurements today with a digital voltmeter of the regulator/rectifier and the battery. Here are the numbers I got so maybe someone can lead me in the right direction on finding my problem.
1. Tested stator output at the rectifier plug- 47.8 volts ac
2. Tested rectifier/regulator @ dc volts output- 12.7 volts dc
3. Battery test with everything off including engine- 12.85 volts dc
4. Battery test with engine running at full speed- 12.6 volts dc
I can't pinpoint my problem; so any input from someone would be greatly appreciated. Thanks
Looks like your regulator/rectifier is bad, by the numbers you posted. Take a look at the testing procedure in this manual to see if you ran you tests correctly. The procedure is the same for all command engines.
I looked at the service manual and I don't have one of those Kohler rectifier testers; I took my readings using a digital voltmeter. I just put a new rectifier/regulator on the engine about a month ago. These problems seem to have started after the choke cable came in contact with the rectifier/regulator and welded itself across the terminals of the voltage regulator. Could that have caused the problems I'm having now? I put the old voltage regulator back on and both it and the new one tested the same on my readings I posted above. Confused and don't know which way to go. Could the choke cable incident have caused some other problems with say the stator or ignition modules? Thanks
I don't use the Kohler tester, just a multimeter as you did. Your output DC voltage readings are too low. This would indicate a bad regulator/rectifier. If you have one that is mounted to the outside of the shroud, with three spade connectors, you may have a bad ground. Try adding a separate ground wire, which will run from the regulator body to a good engine ground. Also, check the output wire from the regulator all the way back to the battery, make sure it is not bad someplace. I've got a 10 hour day, so I don't know when I'll get to check the forum, but there are a couple other tech here that will be looking into this and hopefully they will have some help.
#5
ILENGINE
Either a bad regulator or bad ground at the regulator. Take a multimeter and with the engine running put one lead on one of the mounting screws of the regulator, and the other lead on a good known ground. See what the voltage is. if the reading is much about a few tenths of a volt, you have a bad ground.
kohler has fought grounding issue at the regulator for years. Have went from a ground wire to a ground strap, to a special silver screw to attach to the ground strap, and back to the ground wire.
When I check with my voltmeter at the rectifier for ground problems; what does my meter need to be set on? Also; as I wrote ; this is a new voltage regulator and I was wondering what is blowing them, the original one and now the new one. Thanks
#7
ILENGINE
When checking for ground issues the meter needs to be set on DC volts. If you have a ground problem the meter will show how much voltage is bypassing the grounding system of the component. If you are having repeat regulator failures I would be wondering if something is causing excessive amp draw. Faulty or shorted electric clutch. or something else in the system.
As I stated earlier about the choke cable came across the terminals of the voltage regulator/rectifier and welded itself to it. Ever since then these problems has occurred but I can't pinpoint what is failing. All I know is the battery keeps discharging as I mow the grass and it will get so low that the PTO clutch won't engage and I'll have to charge the battery back up to finish mowing. You can put a voltmeter on the battery and start it up then turn the blades on and you can watch the battery start to lose voltage on the meter. Maybe adding this extra info can give you a better way of pinpointing my problem. Thanks very much for your input.
#9
ILENGINE
without the engine running what voltage are you showing at the B+ terminal on the regulator with the wires connected. Should show battery voltage. Depending on how the system is wired may have to turn on the key to get voltage. The other possibility could be the short that was caused by the choke cable may have melted some wires together in the wiring harness, causing a short which is overloading the regulator leading to failure.
I got 12.7 volts dc at the rectifier. Are you talking about the wiring harness at the rectifier maybe have shorted something out there? I know this has been a pain trying to get figured out. Like I stated earlier I really appreciate your responses. I had 47.8 volts ac coming out of the stator; does that voltage sound normal?
#11
ILENGINE
Would be normal for the 20 amp charging system. May need to what looks like a bad regulator, but with new regulator we may need to do an amp output test to find out how many amps the system is putting out, and to make sure the system is not overloading the regulator causing it to burn up. The claw type amp testers would work best for this test.
The short that was create when the choke cable welded inself to the regulator could have overheated the wires someplace in the wiring harness and now a couple of wires are fused together causing a short, or causing an excessive amp draw.
I have one of those circle clamp amp meters but don't really know how to use it. Where would I need to check and what type setting on the amp meter? Thanks
Thank you IL for chiming in, it's been along day. I don't want to confuse the subject but if the measurements are the same as post #1 this is what I think. AC voltage is fine, which means stator is go. DC output voltage is too low, should be a minimum of 13.4 VDC. that means the regulator is bad. First thing I would do is bolt a new ground wire to the regulator and retest DCV, to see if it increases. You don't have to have the regulator mounted, just bolt a wire throughout the mounting hole. If the is no change I say look intoa new regulator.
Now, why did the second one blow? I agree with IL, you need to look for a short in the B+ wire leaving the regulator going back to the battery. Most times this wire goes either directly back to the battery or is connected to the battery terminal on the solenoid. You may have to disassemble the wiring harness to physically chck the wire. Don't rely on checking the wiring by testing resistance from the terminal end to ground. You could easily get a false reading, as the wiring could be shorted in the harness through another component. At this time I would not install a new regulator in the system, until I was positive that I had a good clean ground and the B+ wire was not shorted.
One test I have used to test amperage is to hook my multimeter inline between B+ output terminal and the battery, test on DC amperage 10AMP fused. You most be careful doing this, as if you have an amperage spike, you could burn out your meter very, very fast, less than 10 seconds.
Hey Thanks guy's; this will give me somewhere to start at to try and find my problem. I really appreciate what you guy's have done. I'll check back with you and let you know how it goes. Again Thanks
Rivets; on doing the amperage test with your multimeter ; where and what color test leads do you hook where? Thanks
#16
ILENGINE
Great you have a clamp type amp meter. Depending on model you would set it on DC amps, I would set it if you can for at least 25 amp range. Can connect either around the + battery cable, or the wire coming off the + terminal of the regulator. a + reading means charging, a - reading will give you discharge.
On some mowers they ran the battery wire going to the regulator through the key switch, this is normally used when the mower has a dash mounted charge gauge. Every body was thinking that if you didn't disconnect power to the regulator it would discharge the battery, which was false.
Meter set on DC AMPS highest range you have. Red lead goes to the DC output terminal, Black lead goes to the positive post on the battery. This is with the regulator unplugged. Test should be taken between 3400-3600 RPM's.
Rivets, ILENGINE; After doing some probing on the mower I recalled something that I'd like your input on. I can't remember if this started after the choke cable shorting across the rectifier/regulator but the RCM switch that you use to back-up with the PTO engaged now the mower can back-up without killing the engine while your mowing. I got to wiggling around at the ignition switch and you can just barely touch it and the mower starts running all rough and wants to die. Could this be a potential problem why the battery won't charge and blowing the rectifiers. Also; I was looking by the rectifier and I can't find a ground wire or strap nowhere. Thanks
I don't know if IL will agree with me but from your last post, I think IL was going in the right direction in post #11. You definitely have a short somewhere. At this time you are going on hide and seek excursion. There is at least 1 short (maybe more) hiding and you are going to be the searcher. This may mean tearing apart wiring harnesses, testing every component, and then starting over because you missed something. You are going to have to follow the number one rule of electrical troubleshooting. ASSUME NOTHING AND DOUBLE CHECK EVERYTHING. A good aid would be to get a good clean wiring diagram of the unit. I don't envy you at this point, you may find it in the first hour or it may take ten hours. Don't over look all safety switches and the key switch. The key switch and the RCM sound like they are bad for sure. A good helper would also be invaluable. IL may have some other suggestions, which are better than mine. Keep us posted.
#21
ILENGINE
I agree with rivets in his short theory. If there isn't a wire going from one of the regulator mounting bolts on the plastic blower housing to one of the blower housing mounting bolts, or some other location to ground, or a silver bar like strap going between the regulator mounting bolt, and the cover bolt just below it. You will need to make a wire with two clamp on rings and install it to ground the regulator. if the regulator isn't grounded it will not charge the battery.
Rivets, ILENGINE; I thought I'd give you guy's a follow-up on the situation I've been dealing with. I put a new ignition switch, rectifier/regulator and added a ground wire to the regulator and now it seems to be working correctly. When I tested the battery before cranking it up it was showing 13.7 volts and after I cranked it I checked it and it was 14.3 going to the battery. Seems like that may have been my problem. Thanks you 2 guy's for your much needed info. I know who to check with if I have anymore problems.
I couldn't tell you which one of you was more deserving but I want to sincerely thank both of you for replying and helping me with my problem. I hope that was the problems; it seems to be doing fine right now. Again thanks; and have a great summer!!!!!!!
I have a Cub Cadet LT1050. The PTO would not stay engaged. It kept going on and off. So I replaced the switch. It still did it, so I replaced the batter with a new one. It is still doing it, and the battery light is turning red, like it it not charging. How do I need to fix this.
Go to the beginning of this thread and use the manual to instruct you on how to test the charging system. Make sure the battery is fully charged when doing the tests. Report back what you find and we will work with you after reviewing your results.
This sounds like the stator (alternator) was damaged by too much current being drawn. I haven't looked it up, but the voltage coming out of the stator sounds high.
