The JLG 40F Boom Lift Dilemma

[demodude]

Wow...Thanks for the welcoming posts

Hey Guys,
First of all..."Off" thanks for the perfect pdf wiring diagrams.
I'm going to print them up and compare them to my basket wiring.

Friday the 40F is going to a job in the city without ''boom" and "swivel" basket controls. We figure we will operate it from the ground controls which work fine.

THE STORY:
One day the machine started lifting and swivel to the left when ground control was switched to basket controls. "boom and swivel" controls had no affect.

All controls on ground work fine.

We found that if we connected a hot jumper to the "clear" relay in the electrical box behind the hour meter it would close the relay and stop the ghost movement. but still have no boom and swivel at basket.
Though we have checked for obvious loose connections we could have missed something as there is a lot of wiring on the unit.

I pulled the 2 berteu controllers in question and thought about replacing them as the pot on one controller seemed loose. Till I found out they were about 550.00 each. The pots checked out with an ohm meter.

Question:
- Should there be approx 4 to 6 volts at the 2 coil terminal screws when
controllers are in the neutral position? (with no wires attached to these)
- I have a 12 volt reading coming back through one of the coil wires when it
is not connected to the controller unit. I felt that was weird
(controllers in neutral )
-One of the electrical components (resister or diode) seems to get very hot
on boom controller.

I have tried to use some of the previous threads to help me get to this point but welcome you thoughts.

Thanks again everyone.

 

[demodude]

BTW...The "drive" controller works OK...and the toggle switches for the other controls seem fine for now...Thanks again.

 

[willie59]

Hi demodude, go back to page 7 of this thread and read post #99. It will give you an idea of how the PQ controllers work with Bertea valves.

 

[jyuska]

Good afternoon. It appears it is very difficult to find any info on the JLG 40G. I believe you had mentioned it was close to the 40F. Could someone please email me all info/schematics you have on either one? I really appreciate the help.

 

[OFF]

Good afternoon. It appears it is very difficult to find any info on the JLG 40G. I believe you had mentioned it was close to the 40F. Could someone please email me all info/schematics you have on either one? I really appreciate the help.

Welcome jyuska

The 40G was a fine little machine. Not many of them around so info is hard to find. You've got mail.

 

[OFF]

It would be really, really, nice to see some pictures of a 40G

 

[ohiojoe]

I have a 30G which looks just like a 40F and am having a problem with the racine proportional controls for boom lift, rotate, and drive. Boom up works great, boom left works great, drive reverse works great. Boom down, boom right, and drive forward works very slowly unless i use another function to "speed them up". Boom down works if I boom left just a little, boom right works if I boom up just a little, etc. Any idea whats going on...thanks for any help.

 

[willie59]

Welcome to the forum ohiojoe. :usa

I have very little experience with Rexroth control valves, not sure what's causing your problem. Try sending an email to OFF, he has much more experience with them. You can click on his name at the left of his posts and access contact info for him.

 

[ohiojoe]

Sorry, I meant Racine valves. They are PQ controllers for lift, swing, and drive. hope this makes the solution to the problem easier.

 

[willie59]

Sorry, I meant Racine valves. They are PQ controllers for lift, swing, and drive. hope this makes the solution to the problem easier.

No worries. If you do in fact have Racine valves and PQ controllers, you should try and send OFF an email. He only pops in here ocassionally and he knows far more about Racine valves than I do. We'll do what we can to resolve your problem.

 

[OFF]

I have a 30G which looks just like a 40F and am having a problem with the racine proportional controls for boom lift, rotate, and drive. Boom up works great, boom left works great, drive reverse works great. Boom down, boom right, and drive forward works very slowly unless i use another function to "speed them up". Boom down works if I boom left just a little, boom right works if I boom up just a little, etc. Any idea whats going on...thanks for any help.

Welcome ohiojoe
Very interesting problem. I'll dig into the schematic tomorrow and see if I can help pinpoint the problem. I just got home after driving 12 hours and my head is spinning hopelessly in neutral. ointhead

 

[willie59]

Welcome ohiojoe
Very interesting problem. I'll dig into the schematic tomorrow and see if I can help pinpoint the problem. I just got home after driving 12 hours and my head is spinning hopelessly in neutral. ointhead

LoL...rub the bottle and the genie shows up! Bah ha ha haha :tong

 

[OFF]

Ohiojoe,
I'm thinking it's electrical just because the controllers work in one direction and that pretty much rules out hydraulic issues.
Looks like the power and ground wires to the controllers are running in series. The power is a yellow 16ga wire, the ground is a brown 16ga. Check those wires at each controller and makes sure they are in good condition and well connected to each controller & where they terminate in the basket. Specially the ground. With an ohm meter check resistance from the screw where the brown wire connects to each controller......to basket ground. It should read very close to zero ohms.

Next, in the basket panel, on the connector strip, locate the following wires:
(numbered from the left - numbers might be different but colours should be right)
#4 green and #5 orange are the lift

#6 blue and #7 blue/white stripe are the swing

#13 red/white and #14 green/white are the drive

with a volt meter connected on #4 and #5, basket control, engine off, ignition on, foot on deadman....you should see appox 6 volts as soon as the lift controller is moved from center. By moving the controller in one direction you should see the voltage smoothly increase to approx 9 volts by the end of it's stroke. Moving the other direction you should see the voltage decrease to about 3 volts by the end of it's stroke.

Check that on all three functions using the correct pairs of wires for each.
Let us know what you get.

 

[ohiojoe]

Yes, my feelings also as these functions did work. I will check this evening if it stops raining. Can you send me schematics, as I have found some wires jumpered (not original) on the main control board? Oh, and here's a picture before I got it running.Thank you!

 

[OFF]

Yes, my feelings also as these functions did work. I will check this evening if it stops raining. Can you send me schematics, as I have found some wires jumpered (not original) on the main control board? Oh, and here's a picture before I got it running.Thank you!

Thanks for the picture!! Looks like a 40F with a square base. That boom looks like it's only 2 sections rather than the normal 3 section.
Schematics are on the way

 

[willie59]

Wow, I haven't worked on one of those, neat.

Good gawd, it's got wheels/tires big enough for an 80 footer! Also looks like they used the Fairfield torque hub on the 40G. I notice it also has the power trak on the side of boom instead of on top of the boom like the 40F.

 

[willie59]

I can't explain this to make any real sense, just a wild thought, but I'd check the main ground (earth) connection for the Racine proportional valve coils, meaning take it loose and clean/check the terminals that make the ground connection.

 

[ohiojoe]

Thank you OFF for the schematics. Verified the ground is good from each controller through basket and back to the main board. Voltages: Drive 3.96 centered, 6.87 forward, 0.6 reverse. Lift 3.89 centered, 6.63 up, 0.96 down. Swing 4.20 centered, 0.55 left, 6.75 right. It looks like the diodes on the lift and swing controllers maybe bad as they conduct in both directions. Do you have to remove them from the circuit to test them?
Contacted the place I bought it from and they found a box full of books which goes with the lift, unfortunately none of them are an exact match for the 30G. Now I have manuals for a 30F and a 30GT . I will assume the schematics are the same.

 

[kenrob]

Off:

I also have a JLG 40G that I have been trying to get info on. Would you email parts and/or schmatics info you have? I really appreciate any help.

Ken

 

[OFF]

Off:

I also have a JLG 40G that I have been trying to get info on. Would you email parts and/or schmatics info you have? I really appreciate any help.

Ken

We haven't found any info specific to the 40G yet, but I'll send you what we have on a 40F with Racine valves & PQ controllers. From what I remember it should be pretty close.
And Welcome to the site