JLG 400S woes

[barklee]

I have a 2002 400S that is possessed! It has been sitting for a year and i put it out on a job a few weeks ago. Once its warmed up it only does what it wants to do. The drive will only work in one direction and then speractically thereafter. Then it wont steer sometimes. Then the boom wont either go up or down depending on its mood.....
I had a mechanic look at it yesterday and he said that the lift card was bad, but not the drive card. He messed with it for 2 hours and couldnt get the drive to act up. So i am thinking it is deeper than that, what would cause these intermittent problems? Seems to me there is a wire rubbing or something shorting or maybe even it got hit by lightning? I dont know but the bad card thing seems highly unlikely to me. He said he checked over the boom cables and didnt see anything torn or gouged.

Any ideas?

 

[willie59]

What S/N is that machine? Does it have separate control cards for lift, swing, drive, and flow control? Or does it have the single ADE processor control card at the platform? Is it only the proportional functions acting up? Or are the toggle switch functions affected as well?

 

[barklee]

Dont have the serial handy. It has the separate cards for each proportional function. I dont think any of the toggles are acting up.

 

[willie59]

I'm not a 400S expert barklee, but if the toggle functions aren't affected, doesn't sound like a master power problem at platform controls, neither does it sound like a problem with the enable timers nor foot switch. Very curious that it's only affecting all proportional functions, as each function has its own circuit card. Just to verify, is there any of the proportional functions working proper, lift-swing-drive?

 

[barklee]

I believe the swing has never been in question. Are all the cards wired to a central location in the box that might be acting up?

 

[willie59]

Swing is working proper? That interesting. Some time, it's just as important as what works proper as much as it is to focus on what's not. We have to consider problems with cable going down boom, even if it doesn't have any damaged spots in it, but I only condemn the cable after I've confirmed other components are good.

To answer your question is not so easy. To say there is a central location, yes, there are common connections to things, but from what you describe, I don't think that's the issue. To clarify, you have a problem with lift, drive, and steer, swing function and toggle functions are working proper. That kind of eliminates problem with "central location" theory.

If I can put this simply, which is really not simple, when you step on foot switch, it sends power to 7 sec interval timer on yel/red 2-20 wire. The interval timer switches and puts power on yel/red 2-21, which distributes power to all functions, proportional and toggle functions. If the main power coming to platform were the problem, or the foot switch, or the interval timer, all functions would be affected.

Since your problem seems to be isolated to lift, steer, and drive, then we know it's not a power supply problem since other functions are not affected. This makes it real easy to suspect problem is with control cards for lift and drive, the steer problem is the fly in the soup. Again, lift, drive, steer all share the same power input from interval timer, but unlike lift and drive, steer does not use any form of electronic circuit card controls, it's simply micro switches sending power down one wire or another.

So, we condemn cable going down boom, right? Not so fast, test the switches that operate steer. Two things I've seen happen with joystick mounted steer switches. 1) switch is bad. Typically not hard to find that with a test light. 2) when you operate thumb lever on top of switch, it doesn't fully operate the micro switch and send voltage signal on the wire. This is kinda hard for me to explain how this happens, typically caused by wear on pivot of thumb mechanism. Just sayin, check that steer circuit closely before we condemn boom cable.

If it turns out the steer problem is simply caused the operation of the steer mechanism, then I would suspect lift and drive is a problem of control cards. Before I dig into steer problem, I think I would switch the swing control card with boom lift, see if problem moves from boom to swing. If it does, switch that (good) card from swing to drive as well, see if drive operates proper.

I must say, those cards have adjustments to them, and I've never adjusted those, have no advice on that. I hope some of this info helps.

 

[barklee]

Thanks Willie, i have not had a chance to switch the cards around. I just replaced the drive controller thinking this would be the problem, about two weeks ago. It was a Hindley controller.

 

[bobb]

if you try to adjust the cards (and i dont recomend it) the adjustments are like two 360 degree turns to get any kind of reaction. i dont know how the adjustment cubes work but they may be like reostats where the point of contact is bad. if so turning the adjustment back and forth a few times and stopping at not the same place you started could help. they should be held in place with some sort of thick paint like stuff, or something that resembles silicon. do not ever use silicon to hold them in place. do not ever use silicon on any kind of electrical connectiion or component. normaly adjusting the cards is not needed. if you understand how they work it can make the machine operate much nicer. if you do not know whats going on in there i dont recomend fooling with it too much. as suggested i would try to swap cards. i would also inspect with a fine tooth comb. the power cable near the platform. any flat spot. any bruising. any tape should be taken off and inspected twice. any punctures or pinches. i would operate the machine with someone fooling with the cable near the platform to see if that creates a problem. any moisture in the connections could be a big problem too. i would also try operating from the platform and checking voltage there at the same time....after all this and more and it still dont work theres the hydraulic side to consider. is your power cable in the track still nice and straight? or is it starting to spiral?

 

[barklee]

if you try to adjust the cards (and i dont recomend it) the adjustments are like two 360 degree turns to get any kind of reaction. i dont know how the adjustment cubes work but they may be like reostats where the point of contact is bad. if so turning the adjustment back and forth a few times and stopping at not the same place you started could help. they should be held in place with some sort of thick paint like stuff, or something that resembles silicon. do not ever use silicon to hold them in place. do not ever use silicon on any kind of electrical connectiion or component. normaly adjusting the cards is not needed. if you understand how they work it can make the machine operate much nicer. if you do not know whats going on in there i dont recomend fooling with it too much. as suggested i would try to swap cards. i would also inspect with a fine tooth comb. the power cable near the platform. any flat spot. any bruising. any tape should be taken off and inspected twice. any punctures or pinches. i would operate the machine with someone fooling with the cable near the platform to see if that creates a problem. any moisture in the connections could be a big problem too. i would also try operating from the platform and checking voltage there at the same time....after all this and more and it still dont work theres the hydraulic side to consider. is your power cable in the track still nice and straight? or is it starting to spiral?

I swapped the cards around and the machine is still acting up. I am absolutely convinced there are wires rubbing somewhere. I havent had time to thoroughly inspect the boom cable but i bet that is what it is. Thanks for the help so far!

 

[barklee]

I swapped the cards around and the machine is still acting up. I am absolutely convinced there are wires rubbing somewhere. I havent had time to thoroughly inspect the boom cable but i bet that is what it is. Thanks for the help so far!

I messed with this machine again today. This time the boom lift function doesnt work at all. I swapped the swing card with it and it did work. The drive is so intermittant that its hard to tell if the card is the cause, but i did swap that one also and it worked fine. So with that said, where is the best place to get these cards? i looked a little online and they are very expensive?? Any ideas on a used one?

 

[willie59]

I get PCM boards from Hindley Electronics.

Yes, they can't get expensive.

 

[barklee]

I get PCM boards from Hindley Electronics.

Yes, they can't get expensive.

Thanks I will check that out tomorrow. I wondered if they might have them.

 

[willie59]

I've been purchasing parts from them for years barklee. Good products, and generally a bit cheaper than OEM. Not to mention, from your home state no less.

https://www.hindleyelectronics.com/

 

[Kprice]

I don't have anything helpful to add to this thread, but I do have a question of my own about a JLG 400S. Willie59 seems very knowledgeable for claiming not to be an expert on these. Where would be the best place for me to start asking questions?

 

[willie59]

Welcome to HEF Kprice. :drinkup

Just start a new thread about your machine and question, it's easy to do. And BTW, I'm really not an expert at this, voodoomojo is our resident JLG expert.

 

[Dave@cranetech]

We have also been experienceing the JLG gremlin.
400s when it warms up the swing circuit goes into super slow mode.
When the machine first starts it runs fine but within an hour we are in super slow swing.
I have changed joystick and reostat.
Please help I am frustrated

 

[barklee]

We have also been experienceing the JLG gremlin.
400s when it warms up the swing circuit goes into super slow mode.
When the machine first starts it runs fine but within an hour we are in super slow swing.
I have changed joystick and reostat.
Please help I am frustrated

Im fairly certain with ours it was/ is the control cards inside the upper control panel. Does your machine have these? They are either mounted on the rear wall of the box or under the control panel cover,, i cant remember anymore....
We replaced the drive card and the lift card and the machine has so far been okay. It doesnt get used much though so its hard to say if this is permanent or not!
Rheostat will have nothing to do with the proportion of the swing or any other function with a joystick. This is only meant to control the speed of the toggle switch controls, ie telescope, basket rotate, basket level.
I would also take a reading on your alternator and battery. These lifts are very particular about voltage and if its just slightly too little you will experience issues.
Hope this helps