Grove AMZ-66 manlift--looking for help troubleshooting basket controls

I've checked almost all of the grounding points, cleaned connections and so forth. I tried running a pair of wires from the basket to the lower control panel and that seemed to get the signal light flickering but didn't provide any basket control.
I was completely serious when I indicated I am about "done" with this machine. I am going to devote about another half day to it and will call it quits after that. I work on stuff every day but not as complex as this and I'm just in over my head.

I do have a bunch of electrical schematics but would need a very powerful magnifier to see it well enough to make sense of it.

I did figure out what the little lunar lander thing was after removing it. (tilt alert device)

This has been an exercise in frustration...

Well, did another session with my manlift buddy. I was able to "hotwire" the coil from the battery to get it fired up but was unable to figure out why I don't have any power with the key switch anymore.
I worked on trying to get basket control messing with relays and so forth and essentially got nowhere.
I have put this project on "pause" for now. I think I need to wait for someone that has stronger electronic trouble shooting skills. That is probably my weakest area of mechanical repairs. I can fix most anything but this machine has kicked my butt and I am slinking off with my tail between my legs. I have work to do on vehicles, tractors, airplanes and chainsaws so I hope those go better. lol. Thanks everyone for their help.

Hi all,
My first post here. Thanks for the helpful posts here, gave me some ideas.
I just bought a 1999 Grove AMZ66XT.
Everything seemed to work fine when I checked it out.
On deliver (it had been trucked 100 miles in the rain) the drive wouldn't work. It seemed to want to go in reverse no matter which way the drive control was pressed, forward or reverse.

Problem was, it wouldn't go in the direction necessary to get it off the trailer. So we had it pulled off with a wrecker. Now it is blocking my driveway.

Everything works from the basket except steering and drive.
Steering works somewhat. It will switch from front to rear wheel steering but I can't get the wheels to steer in the full range of travel. Almost like there isn't enough hydraulic pressure to turn the wheels but it doesn't make sense to me that the hydraulics would be the problem; all the other hydraulic cylinders seem to work fine. I would think that if the electrics and the solenoid and manifold valves are working enough to get some steering that the wheels would steer the full range. But maybe it is flaky electics.

The drive only goes in one direction, no matter if the drive lever is put in forward or reverse. And the drive is really jerky, not sure why. The early post in this thread is helpful since it explained how this problem was fixed by someone else. Thanks for that.

I suspect the problem is moisture in the proportional drive controller which also has the steering buttons built into the top of the drive controller handle.

I'm going to dry things out, refresh grounds, pull all the spade connectors and refresh with contact solvent and apply dielectric grease.
Hopefully that'll bring it back to normal.

If not, I'll probably be trouble shooting deeper and maybe looking for suggestions here on this site.

I did get a parts and maintenace manual with the life, which actually isn't much help. There is a reference to electrical diagrams in the back of the binder, but there aren't any schematics to be found.

Has anyone wired 12v straight to one of the solenoids just to by pass all the electrics to see how things are working? The steering solenoids are not porportional, could I just temporarily jump the solenoids to get the wheels during in the right direction so I can move it. What do you think?

Thanks,
Charlie in the Deep South of Vermont

Sawmilleng's son here.

To be honest, I don't know what I did either. I changed the return hydraulic filter and removed the hydraulic suction filter as I didn't know how old or plugged they were (we are still having issues over finding a replacement for the suction filter). The hydraulics did seem a little more lively after the filters were changed/removed.

Only other thing I can think of is we used it quite a bit over the summer on the house, and maybe the solonoids were getting cleaned out of whatever was gumming it up. I noticed the control's behavior seemed to change after running for about ten minutes.

Mind you, it is always a wild guess on what basket control would work properly each time you start it up - my eye twitches just thinking about it.

Even now, the manlift does not like to steer to the full limit unless the drive motors are engaged. This might be a hydraulic pressure issue.

Don't forget there are some pump controls up in the basket - range and speed. Speed will affect the drive motor speed while range affects everything else. I have the range in high most of the time simply because the thing is too sluggish otherwise.

fearofpavement said:

I found a little "lunar lander" device under the engine next to an alarm horn that had some nasty wires on it. What does this device do?
Any ideas? I have a parts book but no manual.

Click to expand...

That's the tilt sensor

sawmilleng said:

....The 4 proportional valves, at least on my machine, can be poked up the butt with a small screwdriver or something like a nail to directly move the valve spool. You should be able to test your drive solenoid to see if the valve, when mechanically shifted, will drive the machine each way...

Click to expand...

Hi Jon and son,

Thanks for your replies.
I got the lift out of the driveway and up into the farmyard driving in reverse, lurching along a foot at a time. Steering with limited steering but with 4 wheel steering managed not to drive over the bank and into the brook.

Now I can leisurely troubleshoot.
Jon thanks for the info regarding manual activation of the proportional valves. Three of the four work manually (these are also working correctly from the platform). But by experimenting with these three, I learned what to expect.

I disconnected wires from the drive porportional valves and manually actived. Nothing really happens in either direction. Interestingly, things have changed since I manged to drive the lift to its current location. It no longer will drive in one direction as it did before. However, it tends to creep in the same direction just with the engine running!

I realize that I can't edit a post on this site, am I missing something? I didn't mean to post the above quite yet.

Continuing: So I suspect the drive proportional valve is gummed up, stuck. I'm going to study the manual and see if you guys have any thoughts before I start taking apart that valve.

Any thoughts on other things to consider regarding the drive?

As far as the steering, it seems to have corrected itself a little but I haven't really tested it as the lift is sitting on soft ground and operating the steering without rolling digs hole.

Thanks!

CharlieVT said:

...So I suspect the drive proportional valve is gummed up, stuck. I'm going to study the manual and see if you guys have any thoughts before I start taking apart that valve.

Click to expand...

Having studies the manual a little, I realize that the solenoids control a hydraulic valve that serves as master to a slave valve that does the actual opening and closing of the related hydraulic circuit. The solenoid activated valve sits on top of the slave valve. The diagram is a little confusing but I think I understand what is going on.

So even if the slave valve is manually activated, if the slave valve is stuck, nothing happens.

My next idea is to remove the end caps of the slave valve (numbered 803 and 404 in the attache parts diagram). That should allow me to see if the valve piston (#802) is stuck. I might even remove it to check for obstructions.

Has anyone done this? Any suggestions what else to consider?

Thanks,
Charlie

(Hey, I found an edit option. I wonder why that was not present for my previous post...)

Success!
Steering: Not sure what I did with respect to getting the steering hyraulics working better, but it seems okay.
My bigger issue was the loss of drive which had gotten progressively worse over a short period of time.
History: Supposedly, it was all working fine when it was loaded on the trailer.
Once here, after a flat bed ride of 100 miles, the drive would only go in one direction and even then would lurch in short intervals traveled. I now think that the drive hyraulics were sending pressure to the wheel drive motors and releasing the brakes for just a second or two, then the pressure would drop and the brakes would reengage.

As posted above, I began to suspect that the main hydraulic valve (I called it the "slave" valve in above post) was stuck. I came to this conclusion because manually pushing on the "master" valve (the manual calls it the "pilot" valve) did nothing to the wheel drive circuit.

So I removed the end cap of the main hydraulic valve of the wheel drive circuit. Here's what I found: There is a spring that is attached to the valve plunger with a bolt. That bolt was not completely screwed in. In the upper image you can see the exposed threads of the incompletely threaded in bolt. I removed the spring and reinserted the bolt to take a picture that makes it easier to see how much the bolt had backed out.

I tightened down the bolt, reassembled the valve, and voila! the drive is working again.

Since the machine had been trucked in the rain, and the platform control panel was wet inside, I naturally assumed that electrics were the problem. But having ruled out electrics, I turned to the hydraulics. Apparently the ride down on the trailer jiggled the loose bolt enough over time to disable the drive so that it would drive in only one direction. After that, in my efforts to drive the unit, hydraulic flow through the valve continued loosening the bolt to the point that the wheel drive didn't work at all except that there was a slight creep going on with just the engine running.

Thanks to all who posted in response to my original query.
I hope this helps some one else who may have a problem troubleshooting the drive system.

"magic smoke"! LOL Love it!

Do you have a repair or parts manual for the AMZ66 or AMZ66XT? I have a cracked union on the bottom housing. Hydraulic oil leaks out rapidly and I think I'm going to have to totally disassemble the unit to weld if up. I need to figure out the best way to do that.

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HI I have and old telescooping lift made by Manlift inc subsidjary of kidde model MZ66 serial no 3255 i am in need of wiring schematics all of the wires in basket control box have been disconnected from the plugs lift is used on the farm to open and close lid on grain storage bins. It sill work but take two people one to operated from lower control and one to go up in basket to oper or close covers. All control at lower station work ok. I sure would like to get the control in basket working so it would be a one person operation. If any one has the schematics please email me at iccsw.ret.jrattei@sbcglobal.net

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If anyone knows how to fix these Groves, I have an AMZ66 that I have given up on. It's located in middle Georgia (about 50 miles S of Atlanta) and I will make someone a very good deal on it. Needs a low boy semi to move most likely.
It runs and everything functions from the lower controls but there's basket control issues and I am out of my realm. I don't need it badly enough to pay someone to fix it. If this sounds like a project one would like to explore, call me at 770-584-9020 and I can provide more info.

pic of Grove AMZ66

On the above pictured unit, show me where to place the charges, lol.

I have a 96 grove amz50xt with 2300 hrs. Machine is fairly clean. I bought this from the original owner. He said he parked it then a few months ago. Then the top basket controls stopped working.
When I push the auxiliary button the joysticks work except forward and reverse. When I press the foot pedal the green light lights up. But whenever I move any of the joysticks the d/s disable and the l/t/s disable lights come on.
I've replaced all the relays in the lower control box.
Any idea what's going on? I'm clueless as to what else to try or to do.

Sounds like the problem with the AMZ50xt is similar to mine in that it was working, I parked it for several months (ok, a year or so...) and then the basket controls wouldn't work.
I tried a number of solutions and finally gave up. I helped a guy load it on a lowboy this past Saturday and he can deal with it now. I wanted the space back...