Lw 4000 Rear Eye Fail

[newboy]

i have a l/w 4000 that has a rear eye fault after washing about 15 cars. if i power down the j/o cabinet, the fault is gone for another 15 cars then returns. while the fault is present, all of the inputs, x-21 and x26 (mid prox) are working fine while washing a car, even though the rear eye fail alert is on the lcd screen. during the rear eye fail, the machine is not measuring the rear of the car.
i have performed the front and rear eye test with positive results. the red, green and amber leds are lit and x-21 is lit when the eyes are blocked.
this machine has two amps. (old style) instead of one amp and two finder relays (new style)
any suggestions would be greatly appreciated.

 

[newhampshiretech]

darn rear eyes.

well if my memory serves me the rear eye fail will only be looked for during a start up test.
if thats right the occurence should be eyes being blocked after the wash has completed and during the test.

first off id say swap relays or change the one in question that was our most common intermittent issue with the old style amps. and the relay in the docking dryers but thats another issue for later.

I cant recall right now and am away from my manuals. I know that the undercarriage eyes share an input cant recall if it is x20 or x21 if its 21 maybe a car entering right on the tail of an exiting customer? blocking the u/c eyes during start up test.

car not leaving in timely fashion or backing up under a stand alone dryer or bucking up under docking dryer set to stand alone mode.

thats all i can think of ill try to get my books to refresh my mind.
happy troubleshooting.

p.s cant remember if the bay length setting ie short or long has anything to do with it. im thinking no but I cant quite recall.

 

[John Spokas]

Another common cause for this is a bent side spray arch SOMETIMES interfering with the eyes during start-up test.
Multiple arch hits resulting in sheer pin breakage can also slightly bend the arch towards the eyes. Eventually enough small bends accumulate into eye blockage. Remove side spray arch and unbend slightly and re-install if this is the case....

 

[lag]

Open up the J3 box.and test the eyes. Turn on output Y41 (rear eye power). Slowly turn the dial on it down,the yellow light(sensitivaty) should not go off until below the 2 setting ,then the red light(relay) should go off shortly after. If they go off any sooner ,you may very well have an eye going bad. 75% of the time it is the black colored(receiver) eye,25% the gray colored(transmiter).

other causes: cars backing up in the dyer, dirty eyes,bad festoon(this would also affect the front eyes also) loose connections on the amp socket,fog in the bay( still an indication of an eye going bad).

A bent arm ,or bad sheer pin would affect the front eyes. Good luck Lag

 

[carwashinkev]

I had a similar problem about 2 months ago. I have the same amps as you. I had over 30 hours in this problem. It would go away for a little while, but return quickly. I finally changed the amp base and that fixed the problem. A list of things I tried first: changed rear eyes, switched festoon wire, straightened arch bar, switched lasermind from another machine, and new amp.
If you change the amp to a new style be advised that there are (2) 11 positions. Use the right one or it won't work. Good Luck!

 

[zed 9]

Lag,
can you explain further how to Turn on output Y41 ( rear eye power ) and is this the same method for the front eye power.

Regards,

zed 9

 

[Ontario Car Wash]

go to to menu output 3 I think and first is front eye/uc, then rear eye push the * button to yes or on and they should be on
wave your hand infront if listen for clicking in j3 from amp
or cup your hand over the grey eye and see if you see a red light like on a remote
I had one that would fill with water after 25 cars and after I drove my self nuts trying to figure it out the water would drain then it would work fine, then 25 cars later wet again, I finally figured out it was getting wet and in the 15 minutes of diagnosing it would drain.
***be sure to turn off eye when ur done
sometimes the light is red but not to bright u will see how much brighter a new one is
good luck

swap the amps and see it starts failing on the front eyes

 

[zed 9]

Lag,
where in the PDQ manual do i find the test procedure for the front and rear T bar eyes.

Regards,

zed 9

 

[Ontario Car Wash]

#63556
page 4 and 5
run diag 1 enter
test output 1 enter
module 4
output line y41 enter
rear eye off press 1 enter to on

then go check for red lite and clicking open up j3 and look for light on y41 in jo and start jiggling wires and amps don't forget to shake the festoon and check connection in j2

 

[zed 9]

Ontario Car wash
thank you for this information, we could have a rain day or two coming so maybe i'll get some time to check this out.

 

[Ontario Car Wash]

ps just for sh$%s check the middle flag and eye is going on and off
if the middle eye doesn't see itself it wont look for the rear eye

 

[soonermajic]

OMG! That is such a PITA!!