1984 L345DT Refurbishment
- Thread starter DSDispatch
- Start date
So I re-sheathed the wiring, repaired a few weathered connections, added new battery cables (thank you Amazon), replaced the alternator with a new one, and got the tractor running again. Good. However, this pesky error-light named "chg" keeps illuminating. Running or not, rpms high or low, the "chg" light is on. It's the one at the end of my finger.
What's the cause? Well, it appears the new alternator is not charging.
How to diagnose?
1. Get yourself a multi-meter. The $20 one from Amazon is fine.
2. Test battery voltage. Mine read 12.7 volts. Good.
3. Next check the ground to the alternator is good. Use the pos terminal of the battery to the housing of the alternator. This reads 12.7 volts, good.
4. Start the tractor and check the voltage on the post (+) on back of the alternator. Pictured here (tip of finger):
This reads 12.7 volts while running. Not good. This should read 14 or more volts. The alternator is properly grounded, but is not charging. Why not? Could be a few things. Let's investigate:
Pull the 3 wire connector and turn the key on and off while testing each of these leads. One of them should show 12v. This is "actuating" the alternator. It's these:
Yay, one of them shows 12v when the key is in the "on" position. I believe this is with the unit running, but I can't remember.
So the alternator is grounded, it is getting charge that says "go", but it isn't charging. This is very likely due to the regulator. The old Kubota regulators are known for playing poorly with new alternators. I should have ordered one from the start. I got this alternator from Reliable Aftermarket parts and placed an order for a regulator too...now I wait.
In the mean time I removed the old one. It's this piece on the firewall:
What's the cause? Well, it appears the new alternator is not charging.
How to diagnose?
1. Get yourself a multi-meter. The $20 one from Amazon is fine.
2. Test battery voltage. Mine read 12.7 volts. Good.
3. Next check the ground to the alternator is good. Use the pos terminal of the battery to the housing of the alternator. This reads 12.7 volts, good.
4. Start the tractor and check the voltage on the post (+) on back of the alternator. Pictured here (tip of finger):
This reads 12.7 volts while running. Not good. This should read 14 or more volts. The alternator is properly grounded, but is not charging. Why not? Could be a few things. Let's investigate:
Pull the 3 wire connector and turn the key on and off while testing each of these leads. One of them should show 12v. This is "actuating" the alternator. It's these:
Yay, one of them shows 12v when the key is in the "on" position. I believe this is with the unit running, but I can't remember.
So the alternator is grounded, it is getting charge that says "go", but it isn't charging. This is very likely due to the regulator. The old Kubota regulators are known for playing poorly with new alternators. I should have ordered one from the start. I got this alternator from Reliable Aftermarket parts and placed an order for a regulator too...now I wait.
In the mean time I removed the old one. It's this piece on the firewall:
Next, I went to work investigating why the tach gauge is not working. I replaced the cable a few weeks ago, but neglected to address this issue while the cooling system was off the tractor and the tach driver easily accessible.
I removed the new cable from the back of the tach gauge and set it aside while I started the tractor. It didn't spin.
I then pulled the cable from its connection on the engine (front right) and illuminated the little tab inside the shaft - it should be going spinny-spinny, but it wasn't. Sad face. Off to the messicks website to find they still make these (yay), but they're (~$130) boo. Such is life. Don't forget a fresh gasket if you're doing this too.
This is the tab inside the engine:
It spins a gear that spins that little tab you can see when you remove the cable:
Now I wait for Mr. Fedex or Mr. UPS to bring my parts.
I removed the new cable from the back of the tach gauge and set it aside while I started the tractor. It didn't spin.
I then pulled the cable from its connection on the engine (front right) and illuminated the little tab inside the shaft - it should be going spinny-spinny, but it wasn't. Sad face. Off to the messicks website to find they still make these (yay), but they're (~$130) boo. Such is life. Don't forget a fresh gasket if you're doing this too.
This is the tab inside the engine:
It spins a gear that spins that little tab you can see when you remove the cable:
Now I wait for Mr. Fedex or Mr. UPS to bring my parts.
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Has anyone put a new regulator on one of these tractors? The new regulator has the 6-pin connector, but also has an external blue wire. It will start fine, but the chg light never comes on and the alternator doesn't seem to be activated. Does this blue wire need to be on a 12v pos circuit from the ignition?
The blue wire doesn't seem to be a ground. A blown fuse confirmed that was wrong! Lol. I got tired before I could run a wire up to the ignition switch and tie into one of the circuits that shows 12v when "on". Any guidance before I try that tomorrow?
The blue wire doesn't seem to be a ground. A blown fuse confirmed that was wrong! Lol. I got tired before I could run a wire up to the ignition switch and tie into one of the circuits that shows 12v when "on". Any guidance before I try that tomorrow?
Ordered a different regulator with a slightly different part number, still says it is compatible with a L345DT. Same issue - not lighting the lamp circuit at dead-engine key on. No actuation power to the alternator, the f-post.
Hmmm.
Some web research indicates the Lamp and IG circuits can be switched on these. Perhaps I'll swapping those and seeing if I can get the lamp circuit going next.
In the meantime, I went to work replacing the tachometer with a new, slightly newer unit. Turns out the part numbers for the tach driver and cable are the same for a tach you can buy new.
After replacing the cable and driver the old tach gauge just spun wildly. Research indicates this meant the inner spring busted...it is 40 years old after all. The sequence of work to repair the old one was dubbed, "watch-like repair", so I opted for another plan.
The new gauge was plug and play except the different shape. I'll need to fab a converter plate of some type, but it works great!
The part number I ordered was 37150-34600, "kubota tachometer assembly". I was lucky to find one at a dealer for $127+shipping.
Now, to figure out the charge circuit!!
Hmmm.
Some web research indicates the Lamp and IG circuits can be switched on these. Perhaps I'll swapping those and seeing if I can get the lamp circuit going next.
In the meantime, I went to work replacing the tachometer with a new, slightly newer unit. Turns out the part numbers for the tach driver and cable are the same for a tach you can buy new.
After replacing the cable and driver the old tach gauge just spun wildly. Research indicates this meant the inner spring busted...it is 40 years old after all. The sequence of work to repair the old one was dubbed, "watch-like repair", so I opted for another plan.
The new gauge was plug and play except the different shape. I'll need to fab a converter plate of some type, but it works great!
The part number I ordered was 37150-34600, "kubota tachometer assembly". I was lucky to find one at a dealer for $127+shipping.
Now, to figure out the charge circuit!!
