testing jp17 to the motherboard only verifies that the wiring to the solenoid control card is good. might i suggest testing cable jps20 - jpw5/jpw6 if you have no luck with the motherboard, something might have gotten disturbed when the card cages were swapped back.

Well here is what i have done as of the writing of this message. Took the plug and wire and is JP17 to the black steering guidance box, tested ohms from wire to wire, end to end, each wire when where the schematic said it went, there was no shorts or opens that i could located. And as i said before i did take the cards out of this truck and placed them in a different truck and they worked. The only differences are the JP17 plug and wire and the motherboard. Now that i have tested the wire, that seems to say that the problem is indeed in the mother board. I have taken the motherboard out and have examined it and really dont see anything wrong. But we have ordered a replacement unit and when we get that then we will know for certain what was wrong with truck.

those large jp plugs sometimes get the pins breaking off the wiring inside the connector. i have also had wiring break inside the cage... not fun. i have yet to see a motherboard go bad but hey anything is possible now that this beast is probaly over 18 years old.

Well with some new testing i am now under the impression that the problem is either in the motherboard or the wiring that goes between the motherboard and the large round circular plug. I pulled the cards out of the truck that i have been working on and in a hunch just pluged them in on another truck and they worked quite well. so that eliminated the powerboard, the filter board, the interface board, the logic board, and the others that are in there. the only things left are the motherboard and the wiring to the large plug.

All i can say is ARGH. Ok all this time we have thought that the problem was in the interface card. Or at least that is what the diagnosis seemed to indicate. Because the interface card is where the components are that let the magic smoke out. And because it is where all the signals come in to activate the steering. Also because of the fact that when you turned the truck on and pressed on the dead man, the steering tire would center itself.

So we got a interface card, put it into the truck, and now the steering tire pegs out to the left side, does not go to the home location, the sol stays on.

Went and placed the interface card that was working back into the rack, and now that one does not work either. At least before I could get the truck to go forward and back but with no steering, now i cant get it to do a dang thing.

the preamp inside the guidance sensor assy dictates what the truck will guide on. to guide on a different frequency this has to be replaced. as for the card cage... sorry i knew i should have kept it, i could have sent it to you. i think you would have better luck finding a scrap 537 than someone having just the cage.

I would not say that i made it exactly to step 6 because the one step was kind of suspicious. Although i did perform the steps all the way through and am fairly certain that there is at a minimum a problem in the interface card. Could be more problems than that. dont know yet.

But I can tell you this much on sat a user damaged the mini mast of one of the two remaining good trucks. So on a hunch i took and parked that truck and took the black box off of that truck and placed it on the truck i have been working on. The steering and wire guidance began working properly on the truck I have been working on. SO we put that one back in service until we can order the pieces needed to repair the mini mast on the one and then also get the parts to make the black box work properly.

So does anyone have a black box for sale that is complete?

Also can someone tell me what determines that freq of the wire guidance?

Thanks and have a great day.

you are observing what the carraige manager sees.
i used to keep a complete card cage with me for these trucks... i threw it out last year i haven't seen one in over 5 years. it is fairly easy to swap cards out in these trucks and sometimes it is the only way to troubleshoot these however thoroughly checking basics first is always a must.
the interface card is what takes the steering tiller inputs and changes them for the steer logic. one thing for you, i might be wrong here but you might have to physically close the deadman switch while running test 018 i really can't remember but an easy thing for you to check and maybe refresh my memory.

also in test018 did you pass step 6?

Ok one quick question, when you are observing the input which comes from the steering encoder, are you observing what the vehicle manager sees or are you observing what the carriage manager sees?

I ask that because if I go into the input test to observe the steering encoder that test functions fine and i can see the encoder ticks from the steering encoder.

Now as for the status lights on the wire guidance box, yes I am somewhat familiar with them. I can tell you that when you are in the maintenance mode and perform test output 18 the estat lights do not change state. So i do know that the deadman or enable signal is not reaching the wire guidance box. I have performed the test listed under the output 18 heading in the manual. and well to me it could either be the motherboard, which i have looked at, or it could be the interface card.

I may not have mentioned this but the origional interface card that was in the truck burnt up two resistors on the card, resistor numbers R44 and R51 which i believe both to be 301 ohm 1 percent resistors. We did have a used interface card in house it was never taged from any of my predicesors so dont know if it was any good or not. It was by placeing this used interface card into the wire guidance box that i was finally able to get the truck to move forward and back but it will not steer.

Stam is correct
If the motor centers on self test both ways that rules out the steer encoder, and steer transistors. It sounds like the steer signal is not getting over the mast cables..

b side overmast cable carries steer tiller signals to the vehicle manager. i'd be checking the mast cables. are you framilliar with the estat lights inside the card cage? they may give you some information.