340U Starting system Woes

-Problem: I can't keep the battery charged. It is a new battery, 2nd in several months due to my error. I surmise the unit is draining the battery when sitting, switch off and I likely need a diode(?) what ever that is, somewhere.

-System: -Delco Remy alternator with batt connection and a 2 wire pigtail. -Voltmeter, new, grounded from neg terminal per installation instructions. Voltage regulator has been completely by-passed peradvice of a IH shop. I am told alternator has built in regulator.

-New coil with internal resistor.

-Voltmeter shows 12/13+ when running. After charging battery to get it started, voltmeter shows 14/16 until properly charged.

-How I have it wired: ( I am using proper gauge wires) -From Alt: Pigtail #2 to Alt Batt Bolt. Pigtail #1 not in use. I do not get a reading when I put a meter it. -Alt Batt bolt to voltmeter on + side.

-From voltmeter on neg side: -Grounded per above. -Wire to starter post. -Wire to ignition switch. -Wire from ignition switch to push button starting switch. -Wire from push button starting switch to starter solenoid.

I Hope this makes sense. I know someone out there can help me.

Thanks SO MUCH in advance-DC

From the description of what you have wired on the 2 voltmeter posts, I do not see how the tractor even starts or runs. I think that you have confused the wiring needed for the ammeter with what is needed for the voltmeter. They are not directly interchangable. The 340 was originally wired with an ammeter and that system worked well for almost 50 years on your tractor. I think that your simplest solution is to buy an ammeter and put it in instead of the voltmeter. The discussion of which is better is just an academic discussion that can be understood by electrical "experts". I think that you will solve a lot of the problems just by putting in the ammeter back in that hole in the dashboard and wire it up with the same wires on each terminal that you have transferred to the voltmeter. But when you do this, GET RID OF THAT WIRE FROM THE AMMETER NEG TO GROUND, or maybe it will burn itself up along with a few other wires.

A correctly wired voltmeter will be hooked up from a battery + (on one terminal of voltmeter) to ground (on the other terminal of voltmeter), in which case it will read volts all the time (some GM cars did this about 15 years ago)...., or.... from the switched side of the ignition switch to one voltmeter terminal(+) and then to ground from the other terminal.

Your tractor used the ammeter terminals as junction block terminals, thus so many wires under each screw. The ammeter has almost 0 ohms resistance, so it acts like a heavy wire conducting all of the electricity for the tractor. Versus a voltmeter which has a high internal resistance, and conducts almost no electricity at all. Your tractor needs the ammeter, unless you understand how to rewire the dashboard wires to eliminate it.

P.S. I taught physics for 32 years, and a lot of the kids would screw up on interchanging the voltmeter and ammeter. Before we bought Fluke meters (with internal fuses) we expected to burn up a few ammeters every year. They are destroyed in a fraction of a second. I checked everyone's circuit before powering it up to minimize the loss of meters. The rule was "you burn it, you buy it, I burn it, I buy it." They learned well, but were sure happy to have me check their circuits before plugging them in.

I have a 340U and have fought with the dash and ammeter, I know that it is not easy. Disconnect the battery when you are working under the dash.

Paul in MN

www.oldengine.org/unfaq/10si.htm

Old: Are you saying that despite the voltmeter
showing a good charge it is not getting to the battery?

Nat 2: I just looked at my voltmeter and sure enough is is at 12/13 with the tractor not running.
Are you saying that I need another switch in the dash connected to the + side of the ignition switch, then to the negative to the voltmeter ground wire and turn that off also? Per previous discussions I have seen, would a didoe, somewhere in the system accomplish the same?

FYI: I did study Bob's diagrams but like I said, electrical systems just throw me. I am not exactly dumb, was raised on a large farm, Served 20 years as a combat officer,( 2 years in Nam) and then served 20+ years as a Nursing Home Administrator. Just trying to get by now and enjoy some childhood days with a few cattle.
Thanks-DC

From what you said above, you GROUNDED the - side of the voltmeter. Since there is a direct path from battery + to the + bolt on the alternator, through the voltmeter back to ground ALL THE TIME, it's no wonder the battery goes dead when the tractor isn't running.

The - side of the voltmeter should be on a switched connection to ground. It should be on the + side of the ignition switch.

I'm not sure about the whole Voltmeter thing, personally. An Ammeter is stock. With an Ammeter, all you have to do is put it in the line between the BAT bolt on the generator and the + on the battery. None of this switch crap.

Sounds like you wired it, THEN went and looked at Bob M's diagrams... and still didn't follow them?