LW 4000 sensor problem : "back out"

[bandali]

First off, I'm a LW4000 newbie. Have owned a 5-bay self-serve for 4 years, and just bought this 2 -bay automatic last month. Both bays have the PDQ LW4000 with Unitec POS II.

BTW - as my first test, I replaced the leaking 1" swivel and boom hose yesterday (on Bay 1) - yeah !

Now, I have this intermittent problem (on Bay 2) that tells customers to "back up" but then it doesn't start. Resetting via joystick to home resolves the problem, but I want to get to the root cause.
The T-bar on the drivers side is closer in on this bay than the other, and may be blocking one of the sensors (I don't know the technical names for the sensors yet). But this T-bar is clamped with U-bolts to the overhead bridge so I don't want to mess with it needlessly. Also, I'm thinking it may have always been like this.

It started a week ago, and does this almost once a day, but I've had a few days with no problems.

The fault code on the printout is always "Entrance Timeout" code 55. Any input is appreciated.

 

[lag]

Do you have a VT (virtual treadle) ?,or floor treadle ( plate on the floor to drive into) ?

 

[bandali]

I have nothing on the floor to drive into, so I presume VT.

 

[koliver]

One of the issues based off of what you said may be the arch blocking the VT photo eyes when it is in the home position. Look to see that the arch is straight up and down and not bent. If it is bent, you will need to straighten it out to help prevent it from blocking the eyes.

 

[lag]

If possible ,the next time it happens,before you reset ,go into the bay and make sure nothing is in front of the photo eyes mounted on the wall. The one you will be looking at will be toward the exit.

If nothing is blocking the back up eyes ,then you may just simply have a dirty sensor. I have also seen these get cloudy looking. You may also have one of the back up eyes going bad.

One other thought. Is your horn working? sometimes people drive in,and stop when the red light comes on the not notice that they are to far ahead ,and without the horn signaling them ,they may not be paying attention to the signs.

 

[bandali]

koliver : the arch "appears" to be straight. Can I push it out some, just to be sure ? As the car faces the exit, are the VT photo eyes on the left (drivers side) or right (passengers side) ?

lag : one of the sensors seems cloudy (mounted on the wall, drivers side). Can I just unscrew the cover and clean it ? Yes, the horn is working. In fact, when the bay is in this "messed up" state, when I physically walk in and obstruct the sensor on the drivers side, the horn continuously beeps.

Is it possible that the bridge may have moved "inside" a little ? As originally noted, the long T-bar on the drivers side appears closer to the sensor in this bay (when compared with the other bay). It may always have been like this, but I don't know for sure (only owned it 5 weeks now).

TIA for all your advice.

 

[koliver]

If it appears to be straight, I wouldn't do anything else. As Lag mentioned, the next time it happens, look where the arch is in relationship to the VT eyes. As for the VT eyes, they are on both the driver and passenger side. You will have a transmitter eye on one side, and a receiver on the other. This goes for both the stop and back up eyes.

Do you know what eyes you have in there? Are they the barrel style (long and yellow)? This style eye was common to cloud up. There is no way to pull the cover off and clean them.

I wouldn't think that the bridge "moved" as it is probably the way the machine is installed as each bay is unique.

 

[lag]

The only thing I may add is that the horn will beep until the next car has been washed, it is activated with the drive forward sign, output y10 .If nothing is blocking the "backup eyes" when you go and check, you may simply have an eye going bad,or a bad connection back to the VT junction box in the bay (sometimes the cables with the eyes are to short,and have to be spliced).

Intermittant problems can be a pain ,but always have been a great way to learn about how your equipment works. Good luck ,Lag

 

[lag]

You may also want to see if you have alot of space between the tire ,and end stop. You may be able to adjust the front limit flag to move the bridge a little forward. Do not adjust if it is close to the stop.


I sure you have already checked ,but make sure the t-bar is straight up ,and down.

 

[raisetheprice]

You may also want to see if you have alot of space between the tire ,and end stop. You may be able to adjust the front limit flag to move the bridge a little forward. Do not adjust if it is close to the stop.


I sure you have already checked ,but make sure the t-bar is straight up ,and down.

I was going to suggest that the front limit be moved toward the exit just a little. I had this same problem...essentially the bridge is stopping where the T-Bar is blocking the backup eyes. You'll know this is happening either 1) the horn keeps beeping even though the car has moved forward or gone. 2) eyeball a straight line between the backup eyes...the T-Bar should be a few inches toward the exit side and out of the backup eyes' line of sight.

 

[bandali]

I think that was it. I fixed it Saturday, as suggested by lag, by moving the front limit by 1" towards the exit. The tire is now very close to the end stop - almost 1" gap remains.
Thanks all for your help - I've had so many customer complaints, but none in the past 2 days !

2 follow-up questions :
- is this "drift" normal ?
- can I bend the end stop to give the tire some breathing space, just in case ?

 

[raisetheprice]

I wouldn't bend the stops...if the front limit ever fails the stops are the only thing that will keep the bridge on the rails until you get a motor run on and it stops. An inch gap is acceptable.

 

[lag]

Sounds like it may have been stopping to soon at the end of the wash before ,the wash you had a fault on.

A couple of things can cause it to stop short. One would be over inflated tires, or your last pass is a slow speed.

When adjusting keep in mind that it will stop sooner on a slow speed(0-3),and coast on a faster speed, a little more(7-9). What I am trying to say is ...check to make sure on the fast speeds it is not slamming into the stops,if not you may have a little more wiggle room. If it continues to run ok ...leave it alone.

I would not bend the stops. BTW...Has this always done this since you bought the wash ,or is it a "new" issue?

 

[bandali]

It's a new issue. I bought it on 6/9/08 and this started around 7/9/08. The previous owner said this happened once maybe twice in the past few years and they just reset it to home.

 

[lag]

OK.. I asked because , I was thinking you may have had an installation problem ,but it does not seem to be. Let us know if it continues , good luck ,LAG.