Help: Electrical question on a Massey Ferguson 50e - Shuttleshift Solenoid

[macgyver118]

I have a Massey Ferguson 50e tractor loader that will not engage in forward or reverse. I have replaced the Vickers solenoid block, and no luck. Fluids are up to correct levels, etc. The pedals cause the relays on the steering column to click, but no solenoid action. I tested current at the solenoid and both of the yellow/red wires, on each side had 12 volts when either of the F/R pedals were pushed??? So I also tested the leads the plug into the solenoids, and both leads on each solenoid have from 4 to 6 volts running to them??? I couldn't find the inline diodes that are in the manual either. It appears the wiring is either shorting out, or something..... Any help would be greatly appreciated.

 

[Delmer]

Basic electrical theory, if it's shorting out, it will blow a fuse or start a fire typically. If the circuit is open (lost connection) you could have voltages that don't make sense. What is the ground for those solenoids? trace that circuit and find out what it does, that's where I'd go next.

 

[tomanyprojects]

Hello macgyver118, I am having the same problem with my 60H backhoe, what was the conclusion with yours? Did you find the problem and fix it?

 

[macgyver118]

Hello macgyver118, I am having the same problem with my 60H backhoe, what was the conclusion with yours? Did you find the problem and fix it?

 

[macgyver118]

No, not yet. But I’m hoping someone will see this that has a clue. I think there is some kind of electrical backfeed in the relays behind the dash that seem to click when the pedals are pushed, or maybe the inline diodes are bad, but can’t find where they are. Frustrating for sure, don’t want to diagnose by replacing parts and hoping I get lucky.

 

[Ronsii]

Some times the diodes are part of the coils... if you can get to both of the terminals on each coil then take a multimeter preferably one with the diode check function and with the wires disconnected from each coil place meter on ohms check and check the terminals... then reverse the leads and see if the reading changes... with the meter on diode check one way you should get a .5-.6 and with the leads reversed it should be a higher number.

The diodes may also be hidden inside of the actual wiring harness or at/in a plug... does the wiring look stock? or has someone been in there before?

 

[macgyver118]

Here is the stock plug to the solenoid, there are two, one one each side, wire apear stock. Voltage at the plugs terminal connectors are all varied around 4 +\- volts each. https://www.dropbox.com/s/dr37j6cqklu6uuu/Photo Dec 17, 17 24 49 (1).jpg?dl=0

Here is the solenoid unit, it is brand new.
https://www.dropbox.com/s/sxgpr4ko0dfrz8o/Photo Dec 17, 17 25 09.jpg?dl=0

This is the box behind the dash, appears to be relays, but don’t see them in the wiring diagram to follow. Wiring appears stock.
https://www.dropbox.com/s/dnslcafworgd5qv/Photo Dec 17, 17 25 48.jpg?dl=0

Here is the wiring diagram:
https://www.dropbox.com/s/duifbva88rn2nsf/Photo Dec 16, 15 46 05.jpg?dl=0

This is the line feed from the starter switch, it has a 15amp fuse and wiring that is NOT stock.
https://www.dropbox.com/s/bchll0cy2y96yl8/Photo Dec 17, 17 26 06 (1).jpg?dl=0

These are the F/R switches, wiring is NOT stock but appears to connect to original wires in the harness.
https://www.dropbox.com/s/bn4ks9uvd9a1brq/Photo Dec 17, 17 26 34.jpg?dl=0

Any ideas where the inline diodes are based on these photos? Or, does anyone notice anything mid-wired or missing? Thanks!

 

[Delmer]

Is there any other wiring diagram? that obviously doesn't correspond to what you have with the relays on the tractor working and no relays in the diagram.

Either need to find the accurate diagram, or trace the wires and draw the diagram as it exists.

 

[macgyver118]

This is the diagram the manual shows. It’s a 30+ year old tractor. Has anyone out there seen these relays behind the dash? Mine were enclosed in a 4x4 electrical box next to the ignition switch. The wiring sure looks original...or at least well done and old, lol

 

[Ronsii]

While I haven't worked on that specific model massey none of that wiring really looks 'stock' especially the j-box with the generic relays in it.

for troubleshooting I would rig up a hotlead with a switch and direct wire it to one of the solenoids just to eliminate this may be a hydraulic /mechanical problem... of course it goes without saying to think out what you're doing to keep things safe!!! ie... don't hot wire something without taking precautions that you won't get ran over!!!!

 

[hookedondiesel]

Hi mtnwings, I have to agree with delmer, I also don't see a diagram for the relays. I'll up a pdf file here (if I can ) with your two relays, 60.62,,,,it shows the connection points for them.
I noticed from your diagram ( by the way, the numbers are very hard to read ) that the light green wire on the ignition switch is also tapped with that black fused wire. You should have 12 volts there with the key on. This green wire supplies 12 volts to your F/R solenoids via their switch..
Sorry, couldn't upload pdf so here's a picture.

 

[hookedondiesel]

I forgot to mention, pin 10 and 11 should have 12 volts from ground on them when your forward or reverse switch is pushed. This is supplied via your green wire from the starter switch according to your diagram. As should 4 and 6 when energized.

 

[Delmer]

While I haven't worked on that specific model massey none of that wiring really looks 'stock' especially the j-box with the generic relays in it.

for troubleshooting I would rig up a hotlead with a switch and direct wire it to one of the solenoids just to eliminate this may be a hydraulic /mechanical problem... of course it goes without saying to think out what you're doing to keep things safe!!! ie... don't hot wire something without taking precautions that you won't get ran over!!!!

I didn't even notice the electrical box from Home depot, really odd on a tractor. So in addition to the options above, you can yank all this junk out and try to restore it to original function.

 

[macgyver118]

Yeah, now that I know this isn't original wiring and relays, I may try that. But, it worked fine before it didn't. So I will try and check the leads, and maybe replace the relays at $10 a piece to see if it is the easy route. If that doesn't work, then rewiring is the plan. So, if I rewire, I'm still unsure of where the inline diodes are or where they go, or where to get them if they have been removed.

 

[macgyver118]

Ok, so I checked the relays. When the key is on, both relays have 12v to terminals 1, 7, 10, and 11. When the F or R pedal is pushed, #4 gets power respectively. Problem is, the F pedal activates one solenoid and then both terminals on the right solenoid and the lower terminal on the left solenoid get power. I am going to rewire this thing but need help. On the solenoid, there are two terminals and what appears to be a ground or stabilizing pin. Can anyone tell me if both terminals are supposed to get 12v and the big one is ground, or does one get 12v and the other is ground with the big terminal just a stabilizer for the plug? I'll post a couple pictures.

 

[macgyver118]

Here are the pics of the Vickers Solenoid, terminals, and plug:
https://www.dropbox.com/s/dr37j6cqklu6uuu/Photo Dec 17, 17 24 49 (1).jpg?dl=0

https://www.dropbox.com/s/6ypcieuj4xhq7ve/File Dec 18, 15 54 14.jpeg?dl=0

 

[Ronsii]

Hey macgyver118, I just noticed you put up a wiring schedule in the earlier post... so after a quick look I see what diodes you are talking about, I was puzzled when you called them inline diodes these are standard protection diodes sometimes called flyback diodes their sole purpose is to prevent the solenoid from generating a voltage spike when it is De-energized. On a simple circuit like this they probably aren't needed and hence you probably won't find them in the 'retrofit' wiring someone installed. In general it is good to use them on all solenoids but is mandatory on solenoids controlled by electronics... but this is a simple battery/switch/solenoid circuit... technically they could generate a spike that 'could' affect the alternator since it has electronics in it but..... probably not

Oh, lots of times these diodes are built in or soldered right to the two taps on the solenoids themselves(best place for them)

 

[Delmer]

Ok, so I checked the relays. When the key is on, both relays have 12v to terminals 1, 7, 10, and 11. When the F or R pedal is pushed, #4 gets power respectively. Problem is, the F pedal activates one solenoid and then both terminals on the right solenoid and the lower terminal on the left solenoid get power. I am going to rewire this thing but need help. On the solenoid, there are two terminals and what appears to be a ground or stabilizing pin. Can anyone tell me if both terminals are supposed to get 12v and the big one is ground, or does one get 12v and the other is ground with the big terminal just a stabilizer for the plug? I'll post a couple pictures.

You should be able to check this in a couple minutes with some jumpers and/or confirm it with a volt and/or ohm reading of the solenoid.

Crazy to try to rewire something without understanding what it is you're rewiring... Have you traced the GROUND side of the solenoid wiring?

 

[macgyver118]

As far and rewiring, I was planning on running the 12v line from the starter switch to feed both F/R switches, then run Connect each F/R switch to + terminal on each respective solenoid. Then ground the - terminals of the solenoid, and if needed, install the TVS in line diodes to prevent voltage spiking, just like the diagram. Then start it up and see if that is the issue. If I bypass all the other wiring, I figure I can rule out the relays and whatever wiring “fix” was done before.

I get power to three of the four terminals when the F switch is pressed, and nothing when the R switch is pressed. “Something” is wrong with the wiring....

 

[macgyver118]

Pretty sure the solenoids aren’t doing what they are supposed to do because one side is getting 12v across both terminals, while the opposing side is gets 12v on one terminal with the F pushed, and nothing with R pushed.