Battery drain & possible diode location for a 12v alternator conversion?

[Eugene]

Dale:

I use the Delco 10SI single wire clone from the auto parts store. I have had no problem with them.

Exchange the current alternator. It's not cost effective to repair the current alternator, You will only save a couple of dollars. The new alternator will/should have a 1 year warranty.

Edit. At the auto parts store, during the core exchange, check to see that the pulley on the new alternator is the same as the old one.

[Jim Becker]

Looks like about 1.5 amp draw, as I said earlier it has a shorted internal diode. . . .

I read that multimeter as set to measure 5 volts with a reading of less than 1 1/2 volts. Without knowing the internal resistance of the meter, I can't use that reading to infer current. I question whether that is high enough to even be a problem.

Maybe something else (or nothing) is going on here. I wouldn't condemn the alternator based on what I see. If nothing else, unhook the wires from the alternator and repeat the same measurement.

[Dale Finch]

If you enlarge the photo of the multimeter, the INDEX is at the 12 o'clock position, making the scale 250mA.
With the wire to the alternator removed, 0amps.
With the wire attached, I read 60+ mA.

Do you concur?

I know meters are designed differently...on this one, the selected scale is always whatever is at that 12 o'clock position.

[Eugene]

Do you concur?

Yes, concur. Amp draw disappeared when the alternator was disconnected. No other appliance turned on - - alternator problem.

Amazon. The diode bridge and regulator is $35-.

My preference. I would have used a digital mult-meter for the current check. Direct reading on the display.

Also I have several of the Harbor Freight digital multi-meters. They are inexpensive, quite accurate, not a big loss when they get smashed up.

Edit: My single wire 10SI's have an amp draw of 5 mA. It would take a while for the 60 mA to draw down a fully charged battery in good condition.

Clean up the battery cable terminals/ends and cable connections.

The battery doesn't appear to be new. Have battery tested or do a voltage drop test. If good, wash top with baking soda and water.

[Jim Becker]

If you enlarge the photo of the multimeter, the INDEX is at the 12 o'clock position, making the scale 250mA.
With the wire to the alternator removed, 0amps.
With the wire attached, I read 60+ mA.

Do you concur?

I know meters are designed differently...on this one, the selected scale is always whatever is at that 12 o'clock position.

Agreed. I didn't see the dot at 12 o'clock and assumed the labeling was fixed and the bar of the knob was a pointer.

Connecting as you did and using it as a volt meter is a very sensitive way to check for a current leak.

[Gary Dotson]

O.K., looking at the pic, I thought the meter was on the 5 amp scale, I stand corrected.

[Dale Finch]

If I understand correctly, it appears the current alternator IS installed correctly, and shouldn't need any additional wiring to prevent battery drainage, and that there is an internal problem. We do have a pretty good local repair shop, but I would rather just get this done...my own tractor is sitting outside pouting & waiting to get in for his servicing!!!
So checked with NAPA, and they have a 1-wire (#2134011SW) in stock. I plan to pick it up tomorrow!

I'll let you know if this resolves the issue, and I thank everyone for their input.

[Eugene]

If I understand correctly, it appears the current alternator IS installed correctly, and shouldn't need any additional wiring to prevent battery drainage.

Correct.

Some times, out of the box, the single wire alternators do not act as single wire alternators.

When you install the alternator, charge up the battery. Shut off the tractor. Conduct the amp draw test again. There should be an amp draw in the single milliamp range - - normal.

Operate the tractor at half to fast idle to see that the alternator starts charging.

[Dale Finch]

Will do, & thanks, Eugene!

[Mht]

I have purchased 3 alternators from napa with that part number on the last year and they all work perfectly

[Dale Finch]

GOOD TO KNOW!!