1. Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
  2. ALL NEW MEMBERS READ THIS FIRST!! Thank you for joining Heavy Equipment Forums! If you are new to forums we communicate with "Threads", please search our threads to see if your topic may have already been answered and if not then click "Post New Thread" in the appropriate forum. This will allow all of our members to see your question and give you the best chance to be answered. After you've made a number of posts you will graduate to Full Member status where you'll see a few more privileges. Following these guidelines will help make this the best resource for heavy equipment on the net. Thanks for joining us and I hope you enjoy your stay!!

Cat 914G hi/lo not working

Discussion in 'Wheel Loaders' started by NoBudgetMining, Apr 2, 2021.

  1. NoBudgetMining

    NoBudgetMining Member

    Joined:
    Oct 7, 2016
    Messages:
    17
    Location:
    ID-Idaho
    Hey, I have a 99 914G and its stuck in low gear. Nothing happens when you switch to high. I checked the voltage at the switch in the cab and it seems to be working fine. I dove into the manual but cannot make heads or tails of the wiring schematic. I also cant locate the hydraulic Solenoid that changes over the flow. First time working on a hydrostatic! Any ideas?
     
  2. Nige

    Nige Senior Member

    Joined:
    Jun 22, 2011
    Messages:
    17,460
    Location:
    G..G..G..Granville...........!!
    A Serial Number would be a good start. There are 3 different electrical schematics for that model.
    The electrical schmatics aren't usually complicated on a machine that small.
     
  3. NoBudgetMining

    NoBudgetMining Member

    Joined:
    Oct 7, 2016
    Messages:
    17
    Location:
    ID-Idaho
    Serial# 9WM01520
    Thanks.
     
  4. Nige

    Nige Senior Member

    Joined:
    Jun 22, 2011
    Messages:
    17,460
    Location:
    G..G..G..Granville...........!!
    Is this a recent problem.? Were you able to engage HI previously.?
    Reason I ask is that 2-speed was an option on these machines and not all were built with it.
     
  5. NoBudgetMining

    NoBudgetMining Member

    Joined:
    Oct 7, 2016
    Messages:
    17
    Location:
    ID-Idaho
    The machine is new to me and needed a new engine. I got done putting in a new one now IM running it to find other issues it has. I assumed it has hi/lo since the switch is there and hot..all of the other options have blanks where the switches would be. Like the ride control and other options.
     
  6. Nige

    Nige Senior Member

    Joined:
    Jun 22, 2011
    Messages:
    17,460
    Location:
    G..G..G..Granville...........!!
    From what I can see it does not appear as though this particular machine was originally built with the 2-speed option.
    It could have been added later but that info would not be contained in the factory "as built" database.

    Can you post a photo of the Hi/Lo switch, just so we all know which one you are referring to.? Isit the one with the arrow by any chance.?
    upload_2021-4-2_22-35-29.png
     
  7. NoBudgetMining

    NoBudgetMining Member

    Joined:
    Oct 7, 2016
    Messages:
    17
    Location:
    ID-Idaho
    I attached a photo. It is in the same location as the picture you presented.
     

    Attached Files:

  8. NoBudgetMining

    NoBudgetMining Member

    Joined:
    Oct 7, 2016
    Messages:
    17
    Location:
    ID-Idaho
    It also looks like the factory plate displays the turtle/rabbit emblem. I noticed its in a different location than your picture but still portrayed as being far right.
     
  9. NoBudgetMining

    NoBudgetMining Member

    Joined:
    Oct 7, 2016
    Messages:
    17
    Location:
    ID-Idaho
    Was looking around for possible damaged wires and and noticed the transmission speed sensor was broken in half. I tried to push the barbs back in but it eventually snapped in half. I will need to get a new one since this one was most likely damaged during the engine install.

    Do you think those could be a possible link to the hi/lo not operating?
     

    Attached Files:

  10. Nige

    Nige Senior Member

    Joined:
    Jun 22, 2011
    Messages:
    17,460
    Location:
    G..G..G..Granville...........!!
    Potentially. Certainly I would recommend that you replace it before proceeding further with diagnostics. Here is the parts breakdown.
    Latest sensor Part Number is 318-1178, despite the fact that the parts list shows 183-5011.

    I was looking in a bit more detail of the build record of your machine. I found the 2-speed (35km/h max ground speed) attachment hidden in the Power Train Arrangement. So yes your particular machine was definitely originally built with 2-speed.
     

    Attached Files:

  11. NoBudgetMining

    NoBudgetMining Member

    Joined:
    Oct 7, 2016
    Messages:
    17
    Location:
    ID-Idaho
    Thank you for sharing that. So the sensor that is broken is the engine speed sensor (I was wrong calling it the transmission one). But I also located the transmission speed sensor and found it unplugged. It appears that those both send signal to the ecm. I will get a new one on Monday.
    I also understand the system better after diving into this over the last few days. I found out the hi/lo solenoid is burned out. And it is located on top of the fuel tank. When I tested the solenoid its getting power when the hi/lo switch is operated, but not operating the solenoid.
    Hopefully thats the end of the road and fixes the problem. I will update results in case someone else has this issue.
     
  12. Nige

    Nige Senior Member

    Joined:
    Jun 22, 2011
    Messages:
    17,460
    Location:
    G..G..G..Granville...........!!
    Good news that you are getting somewhere. The Part Number of the engine speed sensor will be different to what I posted above. Check the attachment for the correct P/N.

    If you want a P/N for the solenoid it should either be on the schematic or on a tag on the solenoid. I can get it for you if you come up empty in both of those locations.
     
    512high likes this.
  13. Nige

    Nige Senior Member

    Joined:
    Jun 22, 2011
    Messages:
    17,460
    Location:
    G..G..G..Granville...........!!
    The engine speed sensor is Part Number 116-6680. When you install it make sure there is a flywheel ring gear tooth directly under centre of the sensor hole. Screw the sensor in until it touches the gear tooth then back off 2/3 of a turn and tighten the locknut without allowing the sensor to move.

    You might find the attached useful during diagnostics. You can actually get the transmission ECM into Service Mode to check for electronic faults by removing the Harness Code Plug and then powering up the machine by turning on the key. The Harness Code Plugs are shown on Grid I-10 of Page 2 of the schematic. The connector (CONN 35) that they plug into is shown at Grid I-8. The plug is Ref #2 (P/N 116-4232) on the attachment in post #10 above. If it blinks any Codes at you post up what they are.
     

    Attached Files:

    NoBudgetMining and mg2361 like this.
  14. NoBudgetMining

    NoBudgetMining Member

    Joined:
    Oct 7, 2016
    Messages:
    17
    Location:
    ID-Idaho
    Thankyou so much! Greatly appreciated.
     
  15. NoBudgetMining

    NoBudgetMining Member

    Joined:
    Oct 7, 2016
    Messages:
    17
    Location:
    ID-Idaho
    Picked up the speed sensor and solenoid today. Got them both installed and no change. Although I was able to fully test the old solenoid and it was burned out. The problem i think is in the wiring. The hi/lo switch only has 4v of power in the cab, and the plug on the hydraulic solenoid is receiving a constant 8v of power. Regardless if the rocker switch is pushed either way.
    The way I read it is the solenoid will recieve a grounded out signal for lo speed and voltage for the hi speed. Do you know what voltage the cab switch should be at? The switch itself says 24V.. Next step ill do the ECM code reading. Another problem is the battery symbol is lit up on the dash.
     
  16. Nige

    Nige Senior Member

    Joined:
    Jun 22, 2011
    Messages:
    17,460
    Location:
    G..G..G..Granville...........!!
    Try first confirming the voltage across the batteries themselves. Should be 24v.

    Cab switch should have battery voltage I think.

    EDIT: You may not have noticed this ........ in Grid A-3 of the schmmatic is a table of Colour Codes. This table relates to the colours of the wires "as drawn" on the schematic, not the actual colour of a specific wire. The Code refers to what the wire does, or in some cases what voltage it carries. Pay particular attantion to the wires coloured RED that are live with Batt+ when the master switch is ON, and BLUE that are live with Batt+ when the key switch is ON.

    The power wire for the Hi/Lo switch is C742-OR located at D-8 on the schematic. If you follow that wire back to Grid A-6 it connects to wire 308-YL at a jumper (CONN 20). Because 308-YL is coloured BLUE on the schematic it is supposed to have Batt+ when the key switch is ON. Ergo you should have 24v on C742-OR at the speed selector switch.

    upload_2021-4-8_1-34-8.png upload_2021-4-8_1-34-46.png
     
    Last edited: Apr 8, 2021 at 1:37 AM
  17. NoBudgetMining

    NoBudgetMining Member

    Joined:
    Oct 7, 2016
    Messages:
    17
    Location:
    ID-Idaho
    Yes im good on voltage across batteries. Might do some creative wiring. My Only concern is sending to much voltage to the solenoid? IM assuming its 24 volts?
     
  18. NoBudgetMining

    NoBudgetMining Member

    Joined:
    Oct 7, 2016
    Messages:
    17
    Location:
    ID-Idaho
    Thanks for the update. I have the switch removed and with the key on, F747-or-18 has 4.9 volts and is located on pin 1

    The 742-or-18 at pin 2 has 0 voltage. And this is the wire that is suppose to have 24v with key on?
     
  19. Nige

    Nige Senior Member

    Joined:
    Jun 22, 2011
    Messages:
    17,460
    Location:
    G..G..G..Granville...........!!
    You know what.? Do the Blink code test for the Transmission Control from post #13 above. Let's see what it throws up.

    Getting one's head around the electrical schematic is a challenge. It tries to be all things to all men by showing every possible option, and until you read a million-and-one footnotes it is hard to decipher......... I think this is where you came in..!!
     
    512high likes this.
  20. NoBudgetMining

    NoBudgetMining Member

    Joined:
    Oct 7, 2016
    Messages:
    17
    Location:
    ID-Idaho
    I have never looked forward to electronics! I will start the ecm codes in the morning. I ran out of daylight. Re reading the manual for now and will start fresh tomorrow. Thankyou for helping out!
     
    512high likes this.