Farmall 826 Electical issue.

[jim dog]

What does the amp lite mean on my 826 Farmall?  New wireing harness new volt meter alternater tested good. Does the amp lite mean its not charging?  I can't seem to find a wireing diagram of the lite.I installed the new volt meter yesterday, still have the lite. Thanks for any help.

[HydroTek]

charge light for the alternator - also the TA lube light 

[snoshoe]

Still 10 dn with external regulator or 10si with internal regulator.? Makes a difference.

[brahamfireman]

1 hour ago, HydroTek said:

charge light for the alternator - also the TA lube light 

No. 826 they're split.  engine oil on left and amp on right side of fuel gauge.  Lube light is lower on pedestal.

[brahamfireman]

1 hour ago, jim dog said:

What does the amp lite mean on my 826 Farmall?  New wireing harness new volt meter alternater tested good. Does the amp lite mean its not charging?  I can't seem to find a wireing diagram of the lite.I installed the new volt meter yesterday, still have the lite. Thanks for any help.

If it's charging the rear bearing cover will be magnetic,  check it with a screw driver. 

If it's not charging and light is on need to start checking voltage at wires.

Also depends on if it's still got the regulator in pedestal between your feet or internally regulated alternator. 

[HydroTek]

16 minutes ago, brahamfireman said:

No. 826 they're split.  engine oil on left and amp on right side of fuel gauge.  Lube light is lower on pedestal.

Was not certain when the lube light got split off in the models

Really in the shop it was not important to know when the light was added -- just did the tractor have the extra lube light or not 

[snoshoe]

If you installed a volt meter. You shouldn't have to ask if it's charging or not.

 The tell lite provides current to get alternator started. Once started voltage is the same on both sides of the light and it goes out. Circuit between light and alternator differs between external / internal.

[snoshoe]

Going to invoke Ace's right to be wrong. Pretty sure it is hydros that have the extra light. Combination pressure / temp light

[brahamfireman]

22 minutes ago, snoshoe said:

Going to invoke Ace's right to be wrong. Pretty sure it is hydros that have the extra light. Combination pressure / temp light

I'm not a hydro expert but all gear drive 56 series used 3 lights. Oil, lube, amp.

[FarmerFixEmUp]

My 1966 1206 had a separate lube light but my 1967 806 doesn't.  1967 756 does as well as the 1968 1256 and 1970 826 I had. Kind of a different thing in those years on a 1206. 

 

[jim dog]

18 hours ago, brahamfireman said:

If it's charging the rear bearing cover will be magnetic,  check it with a screw driver. 

If it's not charging and light is on need to start checking voltage at wires.

Also depends on if it's still got the regulator in pedestal between your feet or internally regulated alternator. 

 

[jim dog]

Not sure I know what you mean by rear bearing cover.

[snoshoe]

On 8/26/2026 at 10:09 AM, jim dog said:

  I can't seem to find a wireing diagram of the lite.I i

Use 806 diesel with alternator diagram.

[IHC_1470]

He means the back end of the alternator. If it is charging the small needle bearing case becomes a magnet. The small wire plug-in on the alternator does it plug in to the back case from the end or does it come down from the top? Or is it just a single wire alternator using only the battery wire?

[Jeff-C-IL]

Just grab a voltmeter measure the battery voltage - should be 11-12.6V.

Start your tractor.  You may need to rev up a bit.   If the voltage at the battery is 13V or more, its charging.   If it has dropped or stayed the same, its not. 

[acem]

Pics would be very helpful here.

If you have a problem in your wiring system you can have charging voltage at the alternator and not at the battery. The alternator shaft will be magnetized but you won't have charging.

I currently have this problem with my irrigation engine. I believe the amp meter is bad and won't let electricity through to the alternator. 16V at the alternator and 12.5 at the battery. I ran a jumper wire for now.

[jim dog]

4 hours ago, IHC_1470 said:

He means the back end of the alternator. If it is charging the small needle bearing case becomes a magnet. The small wire plug-in on the alternator does it plug in to the back case from the end or does it come down from the top? Or is it just a single wire alternator using only the battery wire?

There are four wires that attach to the back,the two small wires are attached to two wire plug and plug in at the top of the back which are marked R and F. there is also the battery wire and a ground wire.

[jim dog]

4 hours ago, snoshoe said:

Use 806 diesel with alternator diagram.

OK i'll look for that drawing,Thanks

[brahamfireman]

5 hours ago, jim dog said:

There are four wires that attach to the back,the two small wires are attached to two wire plug and plug in at the top of the back which are marked R and F. there is also the battery wire and a ground wire.

That is an internally regulated alternator.  Can't say I've seen many with the R and F markings, most are 1 and 2. 

Are you still using the external regulator in the column between the pedals?

Also you said new voltmeter,  the 826 never had a voltmeter so is it an aftermarket one that you added? 

[brahamfireman]

7 hours ago, acem said:

Pics would be very helpful here.

If you have a problem in your wiring system you can have charging voltage at the alternator and not at the battery. The alternator shaft will be magnetized but you won't have charging.

I currently have this problem with my irrigation engine. I believe the amp meter is bad and won't let electricity through to the alternator. 16V at the alternator and 12.5 at the battery. I ran a jumper wire for now.

That's a completely different issue.

My method will tell you every time if your alternator is good regardless of what a voltmeter says.

Part of diagnosing a no charge issue is determining if the alternator is good. 

[acem]

58 minutes ago, brahamfireman said:

That's a completely different issue.

My method will tell you every time if your alternator is good regardless of what a voltmeter says.

Part of diagnosing a no charge issue is determining if the alternator is good. 

Turns out I have 2V between my alternator case and engine block/ground. Never had that problem before. 

I'll run a ground wire to the block.

 

[jim dog]

1 hour ago, brahamfireman said:

That is an internally regulated alternator.  Can't say I've seen many with the R and F markings, most are 1 and 2. 

Are you still using the external regulator in the column between the pedals?

Also you said new voltmeter,  the 826 never had a voltmeter so is it an aftermarket one that you added? 

I didn't know 826 never had a volt meter. i had the one that was in it tested and they told me it was bad. I stoped at Steiners and they had a replacement.

[brahamfireman]

9 hours ago, jim dog said:

I didn't know 826 never had a volt meter. i had the one that was in it tested and they told me it was bad. I stoped at Steiners and they had a replacement.

Where is the guage located?

Only factory guages in the dash are big round tach on the left and the big combo fuel/temp guage on the right. 

For the 3rd time now......is the factory regulator still installed in the pedestal between the pedals?????

[acem]

The regulator is still installed on my 856 and 826. However they are both running 10SI internal regulator alternators.

A pic of the alternator wiring is needed.

[brahamfireman]

26 minutes ago, acem said:

The regulator is still installed on my 856 and 826. However they are both running 10SI internal regulator alternators.

A pic of the alternator wiring is needed.

It's Not possible to use the external regulator and have an internal regulated alternator work correctly.