More L4000 questions

Just took over a bankrupt wash with two Laser 4000s. Unbelievable amount of error codes on these things. Need some serious forum help here.

On one unit, I kept getting error "Start-Frnt Limit". Ok, I got that. I replaced the front limit prox. Now it works fine for a couple of washes, then it will do this--both soap cycles work fine, but when it goes to hp rinse coming down the driver's side, it will go about a foot, then turn like it is at the back of the car. But I get no error code other than "Impact SW hit". Can reset, and wash a car or two, then does it again.

Other unit will occasionally get "auto ret-fr eye". According to manual it should try to return home every 30 seconds, but it does not seem to. Eyes are clean. How in the world do you figure out which eye is bad when it is intermittent problem?

It is just aggravating because it sends unit out of service after another customer puts money in. Once I power down/up, it is fine for a few washes. I am not being cheap here--local pdq distributor is coming out next week to service, but I just need to get a knowledge base of what causes these issues. Thanks in advance.

Unit one may have a rear limit prox issue. Unit 2 I would try replacing sheer pin first, then work it as if it was an eye issue.

I should add.. You may have festoon issues or other problems, but start with the simple stuff first. Keep us updated, these issues should be fairly easy to solve here on the forum.

lag said:

Unit one may have a rear limit prox issue. Unit 2 I would try replacing sheer pin first, then work it as if it was an eye issue.

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On unit 1, wouldn't that give me the "rear prox" error code if it was bad? I will swap it out tomorrow, just to rule it out. The shear pin is new on unit 2. Why do you think that would affect the eyes?

Sorry for all the questions--I am on a learning mission here. Thanks.

You will get the rear prox fault only when input x27 is on at start up( should be off). I have had x27 "flash" during the wash, and turn into a car as you described. Input x27 should only come on when the prox is in front of tear limit flag.

The sheer pin can wear, and cause the lower arm to block the front eyes. I would look across the eyes, and move the lower arm back to see if it can be blocking the eyes. I have cut some of the foam offthe back of the arm, so the eyes can clear the arm. If this is not an issue , thenyou may need to move on to other solutions, like checking the eye levels on the amps, or a bad feestoon, or even something simple like a loose connection.