I want to thank all of you for your help. The problem turned out to be the new battery although I'm not convinced there was anything really wrong with the first new battery other than causing the alternator light to flash. Both batteries tested good on the load test, recharged ok and started the tractor, but Rural King gave me a replacement. The red light is very sensitive and reacts differently to each of the three batteries which may have something to do with the diode.
red flashing alternator light
- Thread starter labopr
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normde2001
Elite Member
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- Mar 10, 2002
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Does this mean you still have not checked your alternator output?
Soundguy
Old Timer
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- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
Shazam! 15.8 at idle! I'd hate to be that battery at throttle, assuming it goes higher!
I imagine.. 14.7 is about all they would like to see...
Soundguy
I imagine.. 14.7 is about all they would like to see...
Soundguy
slowrev
Elite Member
Yep, will fry some electronics if it has any as well. Has to be a bad regulator. or wiring if external regulator.
Ben
Ben
slowrev
Elite Member
If your alternator is capable of putting out more than a 2-4 amps of current then the high voltage reading is bad and will at the least damage or shorten your battery life. Many smaller lawnmower type engines are unregulated and might put out higher voltages when charging, but do not put out enough current to cook the battery.
Ben
Ben
The 15.85 volts was with the first new battery in the system that made the red light flash. Checking the same with the second new battery I get 12.99 both at idle and at 2000 rpm at the battery. I don't know why the battery would effect alternator output if the voltage regulator was working but the system seems to be working now without any burnt our lights or hot wiring.
Soundguy
Old Timer
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- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
</font><font color="blue" class="small">( I get 12.99 both at idle and at 2000 rpm at the battery )</font>
Hmm.. now another quandry... while 15.8v was 'way high'.. 12.9v is a 'tad low' for charge voltage.. especially 12.9 at high idle. Should really be higher to charge a 12v batter.. more in the 13.2 + to 14.4 14.7 etc. I.E. .. you need more than 12v to charge a 12v battery.. it's an electron/ (potential)/current flow issue...
Do a static voltage check. Check battery volts with tractor and ignition off and see where it sets. then leave meter attatched and check as you start it. Batter 'off' should be 12.5v or so.. then drop during starting.. then jump almost immediatly to 13+v.
Soundguy
Hmm.. now another quandry... while 15.8v was 'way high'.. 12.9v is a 'tad low' for charge voltage.. especially 12.9 at high idle. Should really be higher to charge a 12v batter.. more in the 13.2 + to 14.4 14.7 etc. I.E. .. you need more than 12v to charge a 12v battery.. it's an electron/ (potential)/current flow issue...
Do a static voltage check. Check battery volts with tractor and ignition off and see where it sets. then leave meter attatched and check as you start it. Batter 'off' should be 12.5v or so.. then drop during starting.. then jump almost immediatly to 13+v.
Soundguy
Is your regulator a mechanical? I've seen tons of mechanical regulators fail this way. Another thing to check. If it is an an external regulator ( not integrated in the alternator ) check for a good clean ground. Most regulators will overcharge if they became rusted at there mounting. Seen this a gazillion times too.