Case 680E

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Eugen Canada
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Re: Case 680E

Post by Eugen »

A small update on the fate of this tractor. The original alternator on this machine was replaced by someone in the past with a Delco Remy style alternator. I didn't know much about this alternator when I first saw it. At first look I noticed a broken tab where a connector plugs into it. This type of alternator is called 10SI, and there are some variations. But the one I got has 3 tabs, plus the main terminal that connects to the battery. The three tabs are labeled usually 1, 2, and R. Tab 1 is supposed to go to the positive battery terminal, via the key switch and a light bulb, which is the alternator warning bulb. Tab 2 should be connected to the battery terminal on the alternator. Tab R can be connected to the RPM gauge, but it is usually left alone. All three tabs are coming out of a triangular looking hard plastic device which turns out to be the regulator. Tab 2 was broken right out of the plastic. I carved the plastic until enough of the tab was uncovered and I soldered a flexible wire with a new tab. There are quite a few more pieces on the inside, brushes and brush holder, a diode bridge on a heat sink, a trio of diodes, and a capacitor. I will show how they get measured at some point. The rotor and stator of the alternator also measured fine. The mistake I made when I assembled it back together, weeks ago, was that I did not noticed there is a very cool way to put the brushes in place upon assembly, and the brushes were not sitting right. Therefore I thought the regulator was bust. Looked around for a new alternator, and on account that this is 24V, it's more expensive than the many you can find for 12V. A new one would cost around $200, so I slept on it. Found a rebuilding kit on ebay at only about $100. Again, tonnes of rebuilding kits for 12V, a lot cheaper. For those of you in the US the shipping is much cheaper, and no import taxes; that's why mine went up to the 100. In any case, my ramble is getting too long. I have reassembled the alternator now and traced the wiring on the big backhoe back to the bulb. The whole dial panel on the backhoe is in terrible shape, old, brittle plastic, and the bulb holders were all crumbling from age. My surprise with this alternator is that Tab 1 must be connected via the bulb and to a battery, otherwise the alternator field doesn't kick in, and it produces no voltage. Once this was in place it started producing around 28 volts.

Still, I ordered the new kit and will replace all internal parts, including the ball and needle bearings, basically making it a new alternator. Sorry, no pictures for now.
Case 224, 444, 446, 644, 680E
"Ego is the anesthesia that deadens the pain of stupidity"
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