Hi all New to the site, so far so good! i just bought a Cat 287B skid steer for our company and the back up alarm only works some of the time. I have put power to the alarm itself and it works. Checked the wiring at the alarm and it is fine. Checked the fuse and it is good. My company is now on me because the alarm doesn't work and it is a safety issue. i told them I can fix it. so now i'm here. Where is it located? I am assuming it is under the left controller? I took the grip and the boot off and removed the 3 screws that holds the hydraulics in, but that is as far as i can go. Do I need to remove the heating duct work? and if so how do i get the bolts out on the outside? any help would be appreciated Thanks Pat
An electrical schematic would be your best bet as a start. Post a Serial Number and it's yours .......
Thanks! CAT0287BAZSA01045 I am good with the electrics. It seems like a pretty easy circuit. But I will definitely take the schematic! I dont have a manual for the unit, and it is frustrating. I am really just trying to get to the switch to see if it is making proper contact. It will work sometimes, but not that often.
Believe it or not but the back alarm operates off a pressure switch. You're looking in the wrong place ........
Looks like switch goes up into pilot valve.
Check the simple stuff, first... You low on beeper fluid?
Hand the operator a hand held horn and tell him to mimic the back up alarm with it when he's going backwards. LOL...….I actually saw this.
Is that not located under the left hand control valve? Sorry I'm looking at it on my phone. I'll get a better look when I get to work.
My 287b does the same thing. I find the beeper annoying though. If I am ever in there I may try to unplug the pressure sensor wiring connector.
Yes it is. My bad. I would imagine you access it in a similar way to removing the LH joystick, myabe even have to remove the joystick. Note that according to the Service Manual you need the cab raised.
I pulled off the joystick and pulled the 3 bolts out of the hydraulic bank, but it wont pull out. Ill pop up the cab and see if that makes it easier to get the bolts out of the venting. The only thing now that I am finding is that the bolts to raise the cab have a steel plate around them that I hope just pops off, otherwise i can't get a socket on them. At least I hope those are the right bolts. I am hoping I can just pop off that plate. Thanks
I got the cab up and the ducting removed. The part number matches up as far as I can see it. If i remove this am i going to get fluid?
It's a pilot circuit, loss will be minimal, if not nonexistant.
thanks, is there any way to test this one to see if it works?
Only by applying pressure to it while you have multimeter across the terminals to see whether the contacts close or not. It's supposed to actuate at around 75psi and deactuate at around 56psi.To do that you would require the michaine running. Another way to test it would be to remove the switch from the machine and hook it up to a portapower or similar and slowly pump up the pressure while measuring resitance across the terminals.
Might save $ just to replace the switch, if it aint too pricey...
Or pull it out, clean it, and reinstall to see if anything changes.
$84 (US) for a new switch......
Haha $84 dollars US. I am in northern canada. The land of -25C and paying 40% more for everything. Its $157 here. But I will have it tomorrow morning. When I pull the old one I'll take a look at it and see what it looks like. Thanks for the help everyone. Ill update once it's in. Is it bad that I like when things break on something I just bought so I get to learn more about it?
Pretty much how I learned, or was incentivized to learn, everything I know
Before you replace it try a jumper wire between the two contacts in harness. Then turn key on and get beeper going. Wiggle all the wires and see if alarm is constant. Or drive it to really be sure. Good idea to eliminate any wire problems.
Agree! I always like to PROVE something is bad before replacing it. It sure suck to spend $125 on a switch and the same amount on labor only to find the problem was a loose connection back at the back-up alarm. And don't toss that old switch till you do test it. Being it works off restively low pressures I'd try hooking it up to an adjustable air regulator, say like one used for a paint gun and run it through the on off cycle several times while tapping on it with a small hammer. And if in fact it is bad don't toss it till you cut off the Deutch connector and put it in your electrical parts box. Never can tell when that one will come in handy!
As my old man always used to say - "If you can't take a joke you shouldn't have joined" ...........