Laser 4000 Arch rotate problem

[DavidM]

I hope someone here can help me out. I have tried everything I know of to fix this problem.

On the first car of the day, every day for the last week or so, the arch is over-rotating when it gets to the rear driver's side of the vehicle.
It never over-rotates anywhere else on the vehicle. Originally, it was rotating less than 90 degrees when going back the driver's side of the vehicle but it seems that we have corrected that somewhere along the line but we are still getting an over-rotate on the back driver's side.

We have replaced all prox switches and cables, checked for corrosion in wiring (J2, J3, J4), even removed some wires from wego strip and used wire nuts to make sure there wasn't a problem with the wego terminals.

We replaced the swivel, the cable going to the input card in the JO and probably more that I can't think of right now. Every day we are trying more things and every morning the same thing happens.

Our distributor is ready to replace the gearbox and motor because they don't know of anything else it could possibly be.

Any suggestions?

David

 

[DiamondWash]

Does it over-rotate when in manual mode say at the rear of the bay or when it's in test mode?

 

[DavidM]

It only does it when it is washing a car. I can drive the machine around manually but I can't seem to make it happen. Happening once a day is very unusual. The weather has been good here so we are washing cars all day with no problems.

 

[madscientist]

whenever i've had a problem like this (first car of the day) it has been due to a prox switch/cable that was slowly bleeding or letting power through. it builds up over time so that the prox is charged when it shouldn't be. when cars are running through the day there is not enough time for this charge to build up. for example, it happened on my right limit switch. first car every morning, the trolley would stop as soon as it began to go across the back of the car because the right limit switch was charged. it would rotate and then move forward, hitting the back bumber of the car. it worked flawlessly throughout the day. seems to me like one of your rotate prox switches/cables may be having this problem. i don't have my manual in front of me, so i can't solve the puzzle of which one would be properly carged at 0, 90 & 180, but should then turn off at 270. of course, you said you changed all of these, so i could be way off base.

 

[lag]

going down the drivers side x16 should be on. then when it turns ,x16 goes off ,and going across the rear x15 ,and x17 should be on. Many times in this position x16 will stay on causing the arch to over rotate.

the other issue would be x15 ,or x17 not coming on. Since you have replaced the switches and the cables. I am now looking at the festoon cable as your cause.

Gearbox ,and motor is not the problem.

I am not sure why only the first car would fault out ,but what you may want to do is be the first car to use it. Watch the inputs in the J0 ,and see if 16 stays on ,or if 15,or 17 does not come on. If you would like PM me. I would be glad to help you walk through some steps to correct it. Good luck.

 

[Laser Tracer]

Had the same prob awhile ago. Ended up replacing right limit prox and cable

 

[DavidM]

Thanks for the suggestions so far. At this point my plan is to close the wash tonight, the weather isn't supposed to be too great tomorrow so my father and I are going to go early in the morning and wash a car and watch the inputs to see if we can tell what is happening.

The machine is 8+ years old. The festoon cable was replaced not too long ago.

The right limit prox is intriguing to me. If that stayed on, is it possible that the machine would think it should be turning to the 270 degree position when it should be stopping at the 180 position(back of car)?

Thanks again for the suggestions,
David

 

[madscientist]

i think i misunderstood your original post. is the arch reaching the rear driver's side, then rotating to 180, moving just a little, then rotating to 270, then the bridge moves forward and strikes the vehicle? if so, then your problem is exactly as i described. your right limit prox is slowly building up a charge over night. the first time during a wash that it is a factor is when the arch is trying to cross the back of a car. at that point it is getting a false reading. the buildup is so slow that regular use nullifies the problem, thus the first car issue. i'm assuming you are just finding the arch in that part of the bay sitting at 270. when you watch it tomorrow morning, see if it acts like i described. if so, it is your right limit prox and/or cable.

 

[madscientist]

if i may add, your arch is not over rotating. your arch prox switches are fine. it's rotating as it's being directed to. it's the incorrect message it's getting from the right limit switch, which signals it to rotate to 270 and proceed up the passenger side of the car. it's getting this signal too early.

 

[DavidM]

My dad and I checked things out this morning. I think Laser Tracer and madscientist got it right. There was a current leakage or bleeding problem which is why the fault was only on the first car in the morning. The prox with the problem was the right limit. When I drove the machine from home to the left side of the bay the right limit input stayed lit in the JO.

What appears to have been happening is this.... The right limit prox never turned off after the trolley left home. The machine would go across the front of the car, back the driver side but rather than turn to 180, it tried to go to 270 because the right limit input was on. We have trifoam pods on our machine that prevent the arch from reaching 270 thus triggering the arch rotate fail message.

Thanks again for the help so far, I'll update again when we see if it continues to run or shuts down again.

David