1800 charging problem

chas036 · Mar 20, 2019

My 1800A gas tractor has a one wire alternator that shows 14.25 volts at the alternator terminal and 14.12 volts at the battery terminal which indicates to me that it is working normal and charging the battery. The problem is the red light never goes out. From what I read in the owners manual, this light only is suppose to come on when there is no charge. What could cause this to stay on all the time?

The one thing I noticed on this Oliver vs others, is that to start it you turn the ke on and then push a button that is next to the key. On others of this vintage like 1850, 0r 1650, 0r 1600 that I have started, the starter switch is incorporated in the key.

Bob · Mar 20, 2019

By definition, "one wire" alternators don't need or use an "idiot light".

If your tractor has an alternator "idiot light" and a "one wire" alternator and the idiot light lights (much less when the alternator IS charging), it would indicate that some idiot has connected the "idiot light" up in a useless and misleading manner, IMHO.

rrlund · Mar 21, 2019

Somebody was telling how to make that work right with an alternator. I'd just take the bulb out.

Reminds me of a guy at the tractor club meeting last night. He said he put one of those little alternators on his 77 and couldn't get it to charge. He said it finally dawned on him that it had been positive ground and he didn't switch it to negative when he put the alternator on.

rvirgil_KS · Mar 21, 2019

Are you using the common Delco alternator?
How is the "idiot light" wired?

Some Delco one wire alternators will work with an idiot light or diode added, others will not.

If a Delco alternator, check the 2 pin plug at the rear edge of alternator. If there is a shorting bridge between the two pins you can not use the light. If there is no shorting bridge try connecting the alternator end of the light to the #1 pin on alternator and see if it works.

I have an 8N Ford that came with a 1 wire alternator. I used a diode connected from switch output to #1 and it charges without revving the engine. If it works with diode should work with lite

Bob · Mar 21, 2019

(quoted from post at 08:37:22 03/21/19) Somebody was telling how to make that work right with an alternator. I'd just take the bulb out.

Reminds me of a guy at the tractor club meeting last night. He said he put one of those little alternators on his 77 and couldn't get it to charge. He said it finally dawned on him that it had been positive ground and he didn't switch it to negative when he put the alternator on.

I wonder if the "external regulator" is still in place, and that's what's powering the light?

gary66 · Mar 23, 2019

good news...the light on means it's charging...when it's off then worry.

rvirgil_KS · Mar 23, 2019

Other way around. If working properly, light should come on when switch is turned on and go out when engine is started.

Switch supplies voltage to one side of light, other side goes to ARM or GEN post on regulator. When not running light grounds through the generator and comes on. When engine starts and generator is charging it supplies voltage to ARM or GEN post of regulator. Voltage on both sides of the lamp cancels and lamp goes out

gary66 · Mar 24, 2019

should, but isn't...when it stops charging it will do as all other lights do when it stops charging. If it's on,it's charging. Just a half full glass of water way of looking at it.

1800 charging problem

chas036

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Bob

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rrlund

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rvirgil_KS

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Bob

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gary66

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rvirgil_KS

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gary66

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