Cub Cadet 1440 Amp Light On

[kegrant]

I have a Cub Cadet 1440 Garden Tractor serial 000877203 that I purchased new in 1995.

Yesterday, I noticed the amp indicator light flickered at idle speed. How much? It was a slight flicker for just a split second and then would flicker again in several seconds. The light never came on at full speed when mowing. With the tractor running and I turn the headlights on, at idle speed the amp light is bright red and as I increase the engine speed the amp light gradually dims but never goes fully off. At no time did the tractor ever run differently from before or ever act like the engine was going to cut off.

From your experience with tractors, am I likely looking for a failed part or a short circuit somewhere that is drawing power?

To refresh you memory in case you're not familiar with this garden tractor:

1. The battery negative goes to an engine housing ground.
2. The battery positive goes to the starter as well as the following components in the circuit:

solenoid
relay
voltage indicator
main harness
amp indicator light
engine stator, regulator, armature

Other electrical item information:

Seat safety switch
Reverse safety switch
electric PTO

Thanks for your comments and advice.

Keith Grant
keigrant@comcast.net

 

[George2615]

You may have a little corrosion building up on your connections. Start by pulling and cleaning the battery terminals, then unbolt and clean the ground cable to the engine block. Unhook and clean the battery to starter relay cable connections. Also if you can, check the fluid level in the battery if its not a sealed unit. Top it off with distilled water if low. Clean the top of the battery off with a mix of baking soda and water being careful not to get it inside the battery.
Any little bit of corrosion will cause voltage a drop. Once done start the tractor and check the voltage on the battery. Not running it should be about 12V. when started voltage should increase to about 14 - 14.5 indicating the alternator / generator is working properly. At idle the alternator / generator may not be spinning fast enough to get above 12v thus making your charge indicator light flicker. Clean connections can make a difference. If you don't have 14V at high speed you may need the alternator to be rebuilt.

By the way, welcome to the group Keith.

 

[kegrant]

George,

Thank you very much for your reply.

I don't expect to be able to do any trouble shooting until next week. At that time, I'll try your suggestions regarding connections & corrosion.

By the way, there is no altenator on this tractor.

The battery/electrical and engine/electrical schematics are available at:

' + objMainFrame.arrApplicationTitle['EN'] + ' -- EMPARTweb Version 5.3.1                                                                               

Enter 1440 as the model and then select the first choice for range of serial numbers -- SN #000877203

Again, George, thank you very much for your input.

Keith

 

[Bob_Bainbridge]

You may have a little corrosion building up on your connections. Start by pulling and cleaning the battery terminals, then unbolt and clean the ground cable to the engine block. Unhook and clean the battery to starter relay cable connections. Also if you can, check the fluid level in the battery if its not a sealed unit. Top it off with distilled water if low. Clean the top of the battery off with a mix of baking soda and water being careful not to get it inside the battery.
Any little bit of corrosion will cause voltage a drop. Once done start the tractor and check the voltage on the battery. Not running it should be about 12V. when started voltage should increase to about 14 - 14.5 indicating the alternator / generator is working properly. At idle the alternator / generator may not be spinning fast enough to get above 12v thus making your charge indicator light flicker. Clean connections can make a difference. If you don't have 14V at high speed you may need the alternator to be rebuilt.

By the way, welcome to the group Keith.

Exactly 12 volts would mean that the battery is not being fully charged. 14-14.5 is good for the running voltage but a good battery should read 12.6 volts, not running and fully charged.

Bob B.

 

[kegrant]

Replaced the rectifier/regulator and can measure a difference. While in the repair shop making my regulator purchase, the fellow was talkative and shared some troubleshooting information I’ll add to this thread.

First, with the old regulator, I couldn’t measure increased voltage as I accelerated the throttle. With the headlights on, the amp light wouldn’t go off at highest throttle. With the new regulator, both of these issues have been resolved. So, the regulator was definitely bad, but I now think I either have another issue or perhaps the issue will go away after I mow once and the system has a chance to thoroughly charge.

The current issue is the tractor’s amp light blinks for a split second, only at idle speed, every time my hour meter makes a 1/10 click. When I use my volt meter, I cannot observe any consistent jumping of the needle (30 yr old analog model) that corresponds with the split second blinking of the tractor’s idiot light. If I disconnect the hour meter, the amp light does not blink. Also, I ran the engine at full throttle for about 10 minutes and then back to idle and the light stopped blinking. But, if I turned the engine off and did some other activity for 10 – 15 minutes and then started the engine again at idle the blinking returned.

When I turn on the headlights at idle speed, the amp light comes on. When I increase the throttle to full (normal operating speed) the amp light goes out. Since I rarely use the headlights I can’t confirm this is something new or it was like this when new.

Here are my readings with the new regulator:

13.5 volts at the battery terminals with the tractor off.
13.5 volts at the battery terminals with the tractor running at idle.
14 volts at the battery terminals when I barely increase the throttle to the point where the amp light blinking stops.
15 – 16 volts when run at full throttle.

The fellow at the repair shop explained a volt test I should do of the wiring with the engine off, but switch on to complete the circuit. He told me to test the voltage in the red wire at the regulator to see how much was being lost to the system through faulty grounds.

I obtain:

12 at the red wire connected to the voltage regulator (engine off)
11 at the wires in the wiring harness under the dash. (engine off)

He told me anything less than 8 indicated a significant loss that would prevent charging when the tractor ran.

My questions:

1. Is it normal to lose some voltage in the system from the 13.5 at the battery to 12 at the regulator with the engine off? (Tractor is 11 years old.) If yes, where does it go? Aged wires; not quite perfect grounds?
2. Does the tractor’s voltage meter that controls the idiot light ever go bad? It doesn’t look that expensive. Seems to me that the light is blinking when I can’t observe the same issue with my volt meter needle.
3. At idle throttle, should the amp light come on when the headlights are turned on?
4. How do you troubleshoot the tractor’s volt meter itself, or have I already done that by not obtaining a problem with my volt meter.

I decided to mow (about an acre) the next time and then observe how it behaves after that before I made any further decisions. I was happy when replacing the regulator resulted in increased voltage as I applied throttle and believed I had solved the problem. However, the continued blinking at idle has me stumped. Should I just increase the idle speed slightly? I don’t have a tach to know if it’s set correctly. I do know it has never been adjusted in 11 years since I’ve owned it. I also didn’t want to camouflage an underlying problem by changing the idle speed.

Any advice out there?

Thanks, Keith

 

[Bob_Bainbridge]

Keith, I'm wondering how accurate your voltmeter is. The voltage at the battery with the tractor turned off should be 12.6. You may read a small surface charge for a short time which will raise the reading but turning the headlights on for a minute should drain that and give you the 12.6 reading. 16 volts is a little too high when charging so I wonder if your meter is off perhaps a volt or so. 14-15 volts should be the max to prevent overcharging the battery. I think your amp light perhaps turns on whenever the battery is not actually charging, so if you turn on the lights at idle, the current draw probably equals or exceeds the charging current. The hour meter uses a slight amount of current to "tick" the numbers and may be just enough to cause the light to blink. At any rate it sounds as if you are getting plenty of charging voltage from the alternator to the battery.

Bob B.