JD 690E LC basket case

[mechanick]

Hi guys, first post. I'm new here. Looking for some help, my background is Cranes mostly Manitowoc and Grove.
Anyway I am working on a heavily molested 96 JD 690E. After getting a proper schematic, removing all the "add a fixes" I finally got it running and the ignition switch working as it should. All functions operate but only at idle.
The controller behind the seat has all the red LEDs lit and when you push the test button nothing changes. Does anyone know or have anything on how that system works so I can understand and troubleshoot further. Thanks in advance and sorry for the long winded post.

-mechanick

 

[mg2361]

Welcome to HEF mechanick!

Serial number?

Check all the fuses?

Check the G50 ground wire from the PVC to the battery.

Does your PVC have a decal explaining the lights on it?

 

[mechanick]

MG2361 thanks!

S/N is DW690EL551657 10,115 hrs (working meter)

All fuses good have 27v running on each side of the fuse. Double checked. Case gnd to PVC good also. I run a lead straight to the battery when checking grounds every time.

I downloaded the TM1508 manual (awesome)off A+ manual site.
I checked the G50 ground (brown wire) according to the schematic. I believe I found it on the small connector ( pin cavities are not numbered) and from what I can see in the manual are not really consecutively placed like Left to right but skip around in groups. Really makes it difficult to make sure you are on the right one. I wish I had a better picture of the locations of what pin is where on the connector. My plan was to check all battery and grounds to the PVC first thing.

PVC does have the sticker.
Pushed the test button and nothing changes. However,
Yesterday all lights were red and on solid.
Today I get a pulsing red flash while running but only on:
Red check mode, engine RPM sensor (sensor ohms 3115k, good), pump sol valve, swing brake relay, heavy lift relay, and propel transducer, The propel transducer light is brighter than the others. Maybe I should investigate?

On a side note, I discovered the bypass valve on the function block and engine goes full tilt and all functions operate. It does bog some when multiple functions.

Thanks for the help! This thing was rough. They were jumping the battery relay and start relay to get it running. It now starts and stops with the key, just runs at idle and doesn't seem to stroke the pump as it bogs out the engine. The PVC might be toast but I just wanted to make sure as best I can cause I am not a parts changer lol.

Thanks again!

 

[mechanick]

I think I have it. The engine speed sensor ohms within spec, but when I unplugged it the PVC was happy again. Hit the test button and it cycles through like it should. I removed it and the tip was damaged.
Also found where mice had chewed on the propel transducer wires.
New speed sensor coming tomorrow and fingers crossed we will be in business!

 

[mg2361]

I wish I had a better picture of the locations of what pin is where on the connector.

At some point today (lunch time) when I am at work, I'll send you the PVC pinout locations via PM messaging so you have it. It is in the manual, but very difficult to find.

The engine speed sensor ohms within spec, but when I unplugged it the PVC was happy again.

That is where I would have directed you next after the power/ground checks. Let us know how it turns out when you get the new speed sensor.

 

[mechanick]

At some point today (lunch time) when I am at work, I'll send you the PVC pinout locations via PM messaging so you have it. It is in the manual, but very difficult to find.

Thanks that would be fantastic! I appreciate it!

That is where I would have directed you next after the power/ground checks. Let us know how it turns out when you get the new speed sensor.

I sure will. Just goes to show that just because a component ohms within spec doesn't always mean it is good. I will keep you guys posted, and again I really appreciate the help. I'm just starting out on my own after 25 years in the business. My biggest hurdle other than finding insurance is information. Schematics etc.
Thanks again for the help and hopefully I can reciprocate someday!

-mechanick

 

[mechanick]

Hey guys I got busy as all get out. The speed sensor fixed the issue mostly I also found some more bypassed wiring which I straightened out. Also there was a set of relays next to the door down by the seat frame. Had rotten pins. Fixed all that and she works like a champ. All modes good, I did the engine speed calibration on the PVC box too. Just wanted to post an update. Thanks again for all the help!