8n alternator help

[tmoore81]

I bought a 8n, that has been converted to alternator( pass side) I noticed when battery is hooked up the alternator does not charge, if i unhook it, alternator has 14+ V at the 1 pole, confused to why it would stop charging once battery was connected. tried a 2nd battery but did same thing
im not to familiar with 1 pole style alternators

 

[JMOR]

(quoted from post at 15:01:21 06/19/23) I bought a 8n, that has been converted to alternator( pass side) I noticed when battery is hooked up the alternator does not charge, if i unhook it, alternator has 14+ V at the 1 pole, confused to why it would stop charging once battery was connected. tried a 2nd battery but did same thing
im not to familiar with 1 pole style alternators

ow did you determine that it was not charging?

 

[tmoore81]

(quoted from post at 14:19:46 06/19/23)

(quoted from post at 15:01:21 06/19/23) I bought a 8n, that has been converted to alternator( pass side) I noticed when battery is hooked up the alternator does not charge, if i unhook it, alternator has 14+ V at the 1 pole, confused to why it would stop charging once battery was connected. tried a 2nd battery but did same thing
im not to familiar with 1 pole style alternators

ow did you determine that it was not charging?

My volt meter shows 14+V when not hooked up off the post, and only 12.5 when hooked up( 12.5v is what my battery is currently at)

 

[JMOR]

It will not instantly charge the battery. What is battery voltage after running at speed for 15-20 minutes?

 

[tmoore81]

the second i hook up the battery you can can hear the sound of the alternator change and nearly instant the voltage drops to whatever the battery is currently at, RPM doesnt change anything. I can then unhook the wire to the battery and voltage will go back up to the 14v

 

[JMOR]

(quoted from post at 17:31:29 06/19/23)
the second i hook up the battery you can can hear the sound of the alternator change and nearly instant the voltage drops to whatever the battery is currently at, RPM doesnt change anything. I can then unhook the wire to the battery and voltage will go back up to the 14v

lt feeding battery thru an ammeter?

 

[tmoore81]

no, this one goes direct to + on battery. it has a amp meter on it but looks like its broken

 

[JMOR]

(quoted from post at 17:59:16 06/19/23)
no, this one goes direct to + on battery. it has a amp meter on it but looks like its broken

iven all the info that you have provided, I say that we don't know if alt is charging battery or not.

 

[tmoore81]

as stated before, i know its not charging the battery, as the second the battery gets hooked up to the alternator it goes from 14.4 ish V to the 12.5 ish of what battery is on its own. I have to charge the battery every week or 2. Even after mowing my 5 acre field it would not charge it

 

[JMOR]

(quoted from post at 18:38:22 06/19/23)
as stated before, i know its not charging the battery, as the second the battery gets hooked up to the alternator it goes from 14.4 ish V to the 12.5 ish of what battery is on its own. I have to charge the battery every week or 2. Even after mowing my 5 acre field it would not charge it

ith this "late breaking news", I recommend you take the alt to be tested or substitute another alt just as you did with batteries.

 

[duey]

How snug is the BELT?

 

[tmoore81]

(quoted from post at 19:11:16 06/19/23) How snug is the BELT?

Not super tight but not loose either.

 

[PopsH]

TM - Is the negative terminal of the battery securely grounded?

 

[tmoore81]

yes, lights etc are all grounded off the same battery ground also and they all work fine, tractor starts right up when battery is charged

 

[Eman85]

Sounds odd. Have you tried energizing the alt by jumping the pos post to the place where the other wires would plug into? Where are you hooking your meter to when testing?

 

[tmoore81]

ive tried meter right at alternator post, and at battery get same result, the second the battery is connected to the alternator it stops charging almost instantly

I have a local place that can test them however i have the feeling they are going to say its fine, being it does put out voltage when not connected which i dont think most those test stands have batteries in them but im not sure on that

 

[DennyD]

I'd just take the alternator in to get it looked at by a shop that rebuilds them, and then if necessary, get it rebuilt. (I had a Delco alternator that wasn't charging the 12V battery on my recently-purchased 8N, and took into a local shop to get it looked at in 2021. They rebuilt the whole thing for $100 within 3 days; good as new.)

 

[deanostoybox]

Don't see this question ask yet, so does the alternator have the right pulley on it? It should have a 5/8 pulley and a 5/8 belt. I have seen several 'conversions' where the alternator has a 1/2 belt and the tractors 5/8 belt will not fit so a 1/2 belt is substituted. It will work for a while if the belt is tight enough, but since the belt is running on the bottom of the groove on the crankshaft and water pump pulleys, the belt tends to get glazed and slip on those pulleys causing a no charge condition as the alternator when loaded causes the belt to slip slowing the alternator down too much. Also water pump is slowed and can cause over heating problem.

Just a thought.

<a href=https://www.yesterdaystractors.com/Ford-8N_Alternator-Pulley_AFD5035.html>Alternator pulley</a>

 

[tmoore81]

(quoted from post at 09:36:27 06/20/23) Don't see this question ask yet, so does the alternator have the right pulley on it? It should have a 5/8 pulley and a 5/8 belt. I have seen several 'conversions' where the alternator has a 1/2 belt and the tractors 5/8 belt will not fit so a 1/2 belt is substituted. It will work for a while if the belt is tight enough, but since the belt is running on the bottom of the groove on the crankshaft and water pump pulleys, the belt tends to get glazed and slip on those pulleys causing a no charge condition as the alternator when loaded causes the belt to slip slowing the alternator down too much. Also water pump is slowed and can cause over heating problem.

Just a thought.

&lt;a href=https://www.yesterdaystractors.com/Ford-8N_Alternator-Pulley_AFD5035.html&gt;Alternator pulley&lt;/a&gt;

i can double check this, i know the belt fits on the pulley fine and doesnt stop spinning or anything once battery is hooked up. i can also try going a little tighter on the belt to make sure it isnt slipping at all

 

[JMOR]

(quoted from post at 12:08:16 06/20/23) Sounds odd. Have you tried energizing the alt by jumping the pos post to the place where the other wires would plug into? Where are you hooking your meter to when testing?

man85's suggestion of Batt to Excite &amp; Sense, plus, you can force it to max output by inserting a screwdriver into "D" hole which shorts a tab in the hole to the case. Assuming you have this 10-SI alternator.