Case 580L Series 2 transmission control circuit puzzle

[case580LII]

Hello.

My first post here. I've had my CASE 580L Series2 for 3 years and put 300 hours on it, but intermittently the shuttle won't engage the transmission, especially on first startup after sitting for a while. I think it's an electrical fault or short.

After bouncing the hoe or idling several minutes it usually kicks in and the transmission controls work fine the rest of the day.

During the problem condition, besides the shuttle not engaging, the rear work lights don't work; but if you hit the clutch button, rear work lights go on (and the fan light goes from bright to dim); if you put shuttle in forward or reverse there's no effect on work lights; if you put the shuttle in fwd/rvs while clutch button is depressed the rear work lights will stay on after the clutch button is released.

Does this all point to a common point of failure like the shuttle interlock timing relay? I know it's the odd relay out (I tried swapping around the other relays which are all identical.)

I've got 4wd and the Carraro transmission.

It may be relevant to disclose that the machine has other electrical problems such as: gauges not reading, fuel solenoid not working (manual override in place), and battery drains if I don't put move battery disconnect to OFF when the machine sits.

I have the service manual and electrical schematic, but any tips on where to start or what components to try replacing first would be much appreciated.

Good digging.
-Ryan

 

[Billrog]

Ryan no mechanic here but it sure sounds like you have a problem with a ground wire some place as far as the lights being effect buy the clutch button as well as the fan light. As for the shuttle I have no answer my 580SM is slow to shift into reverse when I first start it up for a few seconds my last 4 backhoes had no hesitation and one was a 580L.

 

[case580LII]

Thanks for the reply. A quick follow-up on my diagnosis: After my post and after I let the machine sit for an hour, I got to thinking about probable causes of a short/fault and I then unplugged the fuel shutoff solenoid harness (since it doesn't work anyway), and started her up; work lights worked normally and transmission engaged; I drove it back and forth for 5 minutes and shut her down; plugged the fuel solenoid back in to see if that was the problem but the transmission still worked normally. If the cause of the fault is in the fuel solenoid, it's got a partial or intermittent short which doesn't always kill the other circuits. I worked the machine hard 12 hours Friday and Saturday and the transmission engaged and worked flawlessly. -Ryan

 

[Billrog]

Ryan you may want to keep the solenoid harness unplugged if it has a short. I've had the harness melt on 2 occasions & there was a lot of smoke & melted wires before I got the key shut off. Then I had to use a piece of hay wire to hold the solenoid open until I could replace it.

 

[case580LII]

Good call; I did leave fuel solenoid unplugged after testing it Thurs night.

Regarding your 580M transmission delay - I've read that the transmission oil pressure/temp might need some time to warm up after a cold start to get the hydraulic clutches to work properly.

-Ryan

 

[Billrog]

Thank you Ryan that's probably the case since in cold weather there's more of a hesitation than when it's warm out.

 

[case580LII]

This is a follow-up on the original question I asked regarding why my transmission wouldn't engage; it still works semi-reliably most of the time, but I discovered two things which lead me to believe the problems is related to the charging circuit and low battery voltage.

1. I was using the work lights grading gravel at night when the transmission stopped engaging; noticed the lights were getting dim so turned the lights off and the transmission would engage again. Insufficient juice to activate a solenoid I guess.

2. I found that the batteries (dual battery) are not charging unless I jump the charge terminal on the alternator. If I jump the alternator the voltage jumps appropriately to 13.6v. I guess there's a problem with the instrument cluster such that it doesn't tell the alternator to charge? I plan to replace the bulbs in the cluster as I understand they're in series with the control circuits such that everything stops working when a bulb blows.

I also plan to check and clean all my chassis to cab to engine block grounds.

Any other tips?

thanks,
Ryan

 

[Billrog]

Voltage regulator is built into the alt maybe it's sticking. Mine does on occasion but as soon as I rev. it up it registers 14+ volts.

 

[hookedondiesel]

Finding electrical problems can be a pain, believe me i know. It's good that you have the electrical schematic for this machine. I'm not familiar with your machine but I can tell you that 13.6V tells me that you still have a drain while running ( if there are no lights etc on ). As stated, you should have a good 14+ volts. Check your schematic and follow the circuit for the "alt" light in the dash console, make sure the bulb is good. With the key "on" the alt light should receive voltage and go to the alt (energizing it), if this doesn't happen, your alt will not charge. Jumping it as you did will work but this tells me you definitely have electrical issues. Check "all" your fuse's, pull them out and check the sockets they sit in for corrosion. Do the same for "all" the relays. The only bulbs in series should be the ones to light the dash up at night. The other bulbs run independently. Check the tension on the fan belt also. Do "any" of the dash lights light up with the key "on". Your ignition may also be wired wrong, who knows if the previous owner played around with the electrical. Good luck.

 

[Billrog]

I'm thinking when things start working as you mentioned in your first post there could very well be a ground problem. It could be in a no. of places but make sure the main battery ground is good where in connects to the frame. Sorry I'm drawing blanks on what to do other than what hodiesel says.

 

[case580LII]

Got up north to do some diagnosis on the backhoe yesterday; on first startup I get these readings on the alternator terminals: RED 12.8v; GREEN 0.35v; YELLOW (tach) 7v; after I jump RED to GREEN terminal, I've get these readings: RED 14v, GREEN 14.1v, YELLOW (tach) 7v. (The 13.6volts I read last time I was up may be due to a drained battery.)

Does that low tach voltage reading mean something is wrong in the alternator? I read it's supposed to be 8v.

I took the instrument cluster home and found that all bulbs are good, but most of the bulb holders are not making good contact with the printed copper circuit material, causing a break in the circuits

I had polished up all the connections some time ago but there's a barely visible point where the brass holder contact has worn through the thin copper coating so it's not making contact with the printed circuit;

To get good contact I turned each bulb holder back about 1/8 turn to a new point on the copper and verified 5ohms across all bulb holder from each side of the printed circuit.

There may be other issues, but this is an clear problem tentatively resolved which may or may not fix my alternator charging and other instrument cluster problems...

Ryan

 

[hookedondiesel]

The tach voltage is a "AC" voltage, so set your meter to ac testing for that one. Sounds about right though, it should be about 7 volts "ac". If you put a test light between the green and red on the alt ( disconnect the green wire from the alt first ), the test light should light up with the key in the "on" position. After the machine starts, the test light should go out. If you follow this, then when you now remove the test light and re-connect the green wire to it,that wire goes to the " alt light " bulb in your dash. You really need a schematic to diagnose this, follow the color coded wires for grounds and make sure they are grounded properly ( look at your schematic for these ), it does sound like you have grounding issues.

 

[case580LII]

After the cluster bulb fix described above, today I put the instrument cluster back in the machine; warning lights now flash on before it starts and the alternator now charges 14.1volts immediately upon startup. Still some gauges to fix, but this is a major step forward.

I wonder if conductive paint could be used to fix the bad contact points on the instrument cluster circuit where the copper is word off. I'm afraid the bulb holders may jiggle back to the "no contact" position and I'll randomly lose functions again.

https://www.bareconductive.com/shop/electric-paint-10ml/

 

[hookedondiesel]

Ya, that paint can be used as you described. You can also put a 560 ohm resister in between the alt bulb wires. This will ensure that "if" the bulb burns out etc, your alt will still get the excited voltage it needs. I also installed an led voltage monitor on my dash. Turn the key "on" and it shows the voltage, when she starts up, it show's the chargeing voltage. Very handy and their pretty cheap on ebay.

 

[hammertime]

I hunted the ground wires and rebuilt the transmission control module hunting the same problem you have. It was the stinkin relay in the middle of the cluster. When it would disengage into nuetral I started fidgeting with them (slightly wiggling) and it clicked on as i wiggled one. I was relived and pissed when I figured it out. Spent a lot of $ on everything else which was working just fine in hindsight. Transmission control module rebuild was almost $1000 in parts.

 

[irncwby44]

Ryan you may want to keep the solenoid harness unplugged if it has a short. I've had the harness melt on 2 occasions & there was a lot of smoke & melted wires before I got the key shut off. Then I had to use a piece of hay wire to hold the solenoid open until I could replace it.

This. Internally the solenoid can be shorted. We replace these with that problem often. Be thankful it didn't melt the rest of your harness (this happens too). I would also check all of your grounds, ground straps, and battery ground. Keep em good, clean and tight.

 

[case580LII]

This is a follow-up to my original post about the CASE 580 L intermittent transmission problem. After 3 years and another 100 hours of good work the machine still would occasionally refuse to engage transmission. Every time I did something to fix it whether cleaning grounds, checking wiring it would start working again and I thought I'd fixed it. But after sitting a few weeks I would start it up to find that it had quit working again.

Sept 2018 I determined to do a thorough inspection of the wiring and found a device behind the fuse box called a "Sentinel Remote Vehicle Disablement Module" which intercepted the reverse relay the and rear work lights. Bingo! that explains why the rear work lights don't work when the transmission won't engage. I removed it and claimed final victory.

But the next week the machine won't move again. Started it again a few days later and it was working..... ???!!#@@!

Two days ago I was pulling logs out of the bush and transmission quit on me... and I noticed it came back on when I hit the emergency brake. After shaking, wiggling, tapping various parts I found the Shuttle Interlock Timing Relay needed to be held a certain way to engage the transmission.

I pulled and reinserted the relay and it's been fine ever since. Probably should get in there and clean all the connections in that panel as a preemptive measure against further bad connections. What's the best way to clean the relay sockets? Flat Screwdriver?

Well, Having identified a specific component that would could turn the problem condition on and off in real time I think I've finally nailed it.

Thanks all for you help and advice.