JD 7420 will not move
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Thread: JD 7420 will not move

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    JD 7420 will not move

    I'm working on a 7420 with a powerquad with left hand reverser that will not move forward or reverse. The code is epc 306040.31 which I believe is "not-neutral switch closed by mistake." I figure this means the wiring to the neutral switch or the switch itself is bad. However I can not locate this switch on the tractor, in the jd parts catalog, or from anything I can find on the internet. What switch am I looking for and where is it located? Any help from the experienced people here will be much appreciated.

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    1010's Avatar
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    Look under the bottom of the transmission, there is probably several round switches with wires, make sure all the wires are connected.
    If one is bad you might have to get JD to come read with a computer. Otherwise it's a guess on the one that's bad.
    We have a 7520 at work that has problems like this. Especially if it's been bush hogging some nasty stuff..
    DRobinson and ttazzman like this.

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    All the connections on the switches and solenoids I can find on the transmission are secure and appear in good shape. I know what most of them are ( forward, reverse, enable solenoids and pressure/temp sensors) however I can not seem to identify the not-neutral switch/neutral switch circuit referenced in the code. I appreciate any help on this.

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    1010's Avatar
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    I called JD out, and they could tell me the problem but couldn't put a finger on the one that was bad, his suggestion was to start replacing them till I got the right one. This was years ago and a young guy so I didn't give him a hard time about it.

    But I had a switch that was tweaked a bit and was just a little wet with oil, so I changed it first and that got it going luckily..

    Sorry the best I can do is point you to this 7420 power quad trans breakdown. -->> John Deere Parts Catalog
    Last edited by 1010; 08-18-2019 at 02:38 PM.

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    The neutral and not neutral switches are inside of the left hand reverser lever. The individual switches are nor sold by deere. You need to replace the entire assembly. Are you sure this is the only code? Have you tried clearing it to see if it comes back? The wire connector for the reverser lever is at the bottom of the steering column. You can check action of the switches in the lever with an ohmmeter if you have a wiring diagram. There is a neutral switch, not neutral switch, forward switch and reverse switch in the lever. The not neutral switch needs to be closed(have continuity) when lever is in forward or reverse. Check for continuity between terminals A & B on connector.

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    Thank you for the info JD110. I checked the connector for the reverser switches as you suggested. Here is what I got; pin A to B closed when lever is moved to forward or reverse, pins C to D closed when lever in forward, pins C to E closed when lever in reverse, pins F and G have 14 ohms together but are open at all lever positions to all pins. I don't have a service or diagnostics manual to check, but am thinking the not-neutral, forward, and reverse switches may be good. Not sure about the neutral switch. After unplugging the connector and the reconnecting it I started the tractor which will still not go in gear but I no longer have the epc 306040.31 code. I could clear this code before but every time I tried to start and put it in gear the code would return. The only code now is bif 00639.02 "29 bit can bus, open circuit."

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    The BIF is the Basic Informator or instrument panel. I would check the fuse F04/13 and diode K09-2. Diode may have been accidently installed backwards or could be defective. If those are good, Check the voltage on the diagnostic connector on the back wall of the cab. Check from pin A to C and voltage should be about 2.6 volts and A to D should be about 2.4 volts. Report back with results and we can go further.
    DRobinson, BigJim55 and Tx Jim like this.

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    Finally received the left hand reverser we ordered. Installed it and the tractor is back in operation. Thank you jd110 for giving me the information that allowed me to track down the problem.

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    You're welcome. Glad you got it fixed.

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