JMOR - ammeter show discharge when running

[BigYoung]

I have searched old posts and tried one of JMOR's wiring diagrams and ammeter still shows a discharge when running.

1948 8n serial # 81104, front mount, negative ground, previously wired for 12 volt, new ammeter, new 12 volt 10 si one wire conversion kit with harness, new paint (ground issue?, new starter and solenoid, buffed starter mount surfaces.

Tested alt by disconnecting positive batt cable when running and keeps running... also checked battery with voltmeter while running and shows 13.9 volts and 12.7 when not running.

Ammeter posts stamped negative & positive. Tested ammeter off of tractor by installing inline between negative and positive leads (neg. batt. lead to neg. ammeter post and pos. ammeter lead motor and then pos. batt. post) with 12 volt motor and ammeter shows a discharge with motor on. Reversal of leads shows a charge.



Kit instructions and JMOR diagram show ammeter wired in positive lead only.

First I wired harness according to kit instructions as shown in first 2 pics then wired according to JMOR Just 8Ns 12v Conversion before SN 263844, and still showing discharge.

Only the coil and starter drawing power and No light wiring yet. Tractor starts quickly and runs smooth on all cylinders, only problem seems to be ammeter showing discharge when it is running and charging. Discharge is initially 30 amps and after a few minutes is down to 10 amps. All suggestions welcome and would like to hear from JMOR. Thanks

 

[BigYoung]

This is the JMOR diagram

 

[JMOR]

(quoted from post at 11:11:55 08/09/15) This is the JMOR diagram

s there a question here?

 

[BigYoung]

Yes Sir, what is probable cause of ammeter showing discharge with tractor running? any suggestion as to what i should check?

 

[JMOR]

If ammeter is good & wired in as shown, then alternator will be the problem. Is yours a one wire alternator as shown in diagram? Put a voltmeter across battery terminals & see if voltage increases after running at half throttle for a couple of minutes. Is your battery going dead over time (not just sitting for weeks, but using tractor)?

 

[notjustair]

You've done all of the tests. It's charging fine and seems to be putting out correct amperages. Looks like a shiny new gauge. They probably made it wrong in whatever sweatshop it was make in. Leave the resistor stuff and switch the wiring on the gauge.

 

[Danny in CO]

Big,

Since you have 13.9 volts when running, that tells me the alternator is fine. I think you just need to reverse the wires on the ampmeter.

Good luck,
Danny

 

[JMOR]

In your picture of back/terminal side of ammeter, tell me what is at other end of the wire on left side of picture & of wire on right side of picture.

 

[BigYoung]

Mr. Morris,

Left side-red wire from alternator. Right side-red wire from pos pole of solenoid. thanks

 

[BigYoung]

Thank you Danny, will give it a try and post back once I read all suggestions.

 

[JMOR]

(quoted from post at 13:13:06 08/09/15) Mr. Morris,

Left side-red wire from alternator. Right side-red wire from pos pole of solenoid. thanks

ove only the right-side (solenoid) wire to the left terminal & move the one left side wire (alt) to the right where it will joint the load wire (black tape) already there.

 

[BigYoung]

Mr. Morris,

Tractor off, battery reads 13.4. Tractor running battery reads 14.3.

I had to reconnect ammeter wires to run tractor and reversed the ammeter connections to alternator lead to negative side of meter and positive solenoid lead to positive side of meter as suggested by NotJustAir with good results.

Started tractor and ammeter needle pegged to 30 amps charging then after a few seconds settled down and shows a charge between 5 and 10 amps.

I've been reading and rereading wiring diagrams for a few weeks while I figured out a hard start and miss issue and this was simple fix. Thanks again for studying on this with me.

 

[BigYoung]

Danny,

You are correct Sir, reversed ammeter connections and tractor shows charging between 5 and 10 amps when running. Thank you.

 

[BigYoung]

Yes Sir, $6.00 gauge. Reversed ammeter leads as suggested and meter shows charging when tractor is running.

Thank you.

 

[BigYoung]

(quoted from post at 16:37:19 08/09/15)

(quoted from post at 11:11:55 08/09/15) This is the JMOR diagram

s there a question here?

Mr. Morris, I'm understanding your post now. I posted in Classic View and you must be reading Modern View which doesn't reflect my first post with details and pics.

We need some cloudy skys and rain down here in Freestone County Texas.