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590 Super L Shift Solenoid Diode Location

Ring47

New Member
Joined
Feb 16, 2020
Messages
3
Location
North Texas
I have a Case 590 Super L Series 1 made in 1998. My rat friends have done some rewiring for me and I am trying to fix it. The machine will go in reverse but will not go forward. I believe I have fixed all of the wires behind the instrument cluster housing, but five wires have been parted in the bundle that runs from the relays area to the front of the machine. They are located about two feet forward of where the bundle drops down through the hole in the floor. Three wires run toward the relays and two wires run forward. My question is where are the shift solenoid diodes located? This is because it appears that there was a connection made at the broken wire location and this may be where the diodes were installed in the harness. I have not been able to find any info in the service manual about the location of the diodes. I fear that my rat friends have removed the diodes and taken them to their home to use as a trophy.
 

JBrady

Well-Known Member
Joined
Jan 24, 2019
Messages
248
Location
NE OK
I would repost this in the TLB section of the forum. I also have a 590 SL Series 1, but have not been into the electrical that deep. I do hate rats though! You may have already seen this in the service manual. It doesn't give the exact location, but does show that they are wired around the fwd & rev solenoids and after the relays, so I'd find those items and start going down wires #26, 27, & 30.

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JBrady

Well-Known Member
Joined
Jan 24, 2019
Messages
248
Location
NE OK
The parts manual is a little more descriptive. Looks like there might be up to 7 diodes (item #2) in the same general area:
upload_2020-2-20_9-35-37.pngupload_2020-2-20_9-36-4.png
 

Ring47

New Member
Joined
Feb 16, 2020
Messages
3
Location
North Texas
Thanks for the help. I don't think it will hurt anything to have additional diodes in the circuit so I am just going to get a couple of diodes and put them in the circuit just to be safe. I have another question for Bootheal. I am new to this forum. What or where is the TLB section?
 

JBrady

Well-Known Member
Joined
Jan 24, 2019
Messages
248
Location
NE OK
This is just the general industry forum. Things that are common to the industry and a catch-all forum. From the home page, scroll down to the first section, i think it is called "earth moving equipment". You'll see that there are specific forums for each type of equipment: excavators, graders, and backhoes (TLB=Tractor, Loader, Backhoe). The TLB site seems to be pretty active and I think if you posted the same question there, you'll have a picture of exactly what you are looking for in an hour or less. There's probably a half dozen or so members that are EXTREMELY knowledgeable about backhoes. Alrman is an expert on Case backhoes.
 

Ring47

New Member
Joined
Feb 16, 2020
Messages
3
Location
North Texas
Thanks very much. However this afternoon after I had gathered the eggs from the chicken house I walked through the area where I park the backhoe. I started kicking the leaves around and behold. I found the two diodes. The wires had been chewed off right at the end of the diode connector. As I had guessed the forward diode had two orange/gray wires and the ground wire. The reverse diode only had the one orange/red wire and the ground wire. I suppose the reverse solenoid wire from the relay to the solenoid is a separate wire, since it will move in reverse. For anyone that has the 590 Super L Series 1 the forward and reverse solenoid diodes are located about mid-chassis and are part of the large wire bundle along the side of the frame. It is underneath on the right hand side. The reverse diode has two wires orange/red and black/orange (ground). The forward diode has three wires, two orange/gray wires (one from the back and one from the front both connected to the same terminal on the diode) and a black/orange (ground). Be aware that after 22 years the colors may look a bit different.
 

Wilson892

Well-Known Member
Joined
Jun 14, 2015
Messages
93
Location
Ontario, Canada
When working on my 590SL the diodes all 7 where located under the instrument panel on right side. The wiring and wire colours are different between the three SL series.

John
 
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