my high speed tracking is working intermittently and i am pretty sure i have tracked it down to an issue in the digital display. my question is that if i bypass the computer and basically run a direct 12v line from the high speed servo to the switch for the high speed will that work? i know i will lose the little rabbit light on the display but i do not care about that.....and i also know that the power to the high speed will not be turned off with the main switch and power will constantly be on if the high speed switch is left on when the machine is not in use.
Need a Serial Number to look at the appropriate electrical schematic.
CAT3018CEJSB02399. thanks.
OK, so from the schematic the 2-speed switch receives power from a circuit controlled by the ignition switch via the hydraulic disable relay. The output from the switch goes straight to the speed select solenoid. As far as I can see the "computer" (do you mean the Monitor system gauge/idiot light cluster in the RH console.?) has nothing whatsoever to do with it. There are a couple of splices inside harnesses that might have something to do with an intermittent 2-speed problem you are experiencing. If you want a copy of the schematic you can have one.
getting the schematic would be great. the monitor system must have something to do with it because there is a rabbit symbol indicator light that goes on when the high speed switch is engaged. I swapped out the relay with an identical relay and the problem still persists...and i also metered the switch for continuity and it is working fine. so if i send 12v power to the solenoid will it engage it no problem? second, can it handle the full amperage directly from the battery, and third is there polarity on the solenoid?
I'll send you the schematic.
do the splices happen right at the harness? i will focus my energy there then....colour GY that goes from solenoid to the relay, BR that goes from gauge group cluster to the switch, YL that is main power, and BK ground to main chasis....
The splices, like the one I circled below, can be anywhere in the harness and not necessarily anywhere near the location the schematic seems to imply. The only way to tell if a splice is the problem is to do the "tug test" by pulling and twisting the harness every which way while running a significant current through the wire in question via a test light. If the light flickers at all something is suspicious in the harness at the area where you are manipulating it. 131-BR carries power to the 2-speed switch. E953-GY is the feed to the 2-speed solenoid from the switch.
oh man....that sounds awful trying to find a break. thanks very much for your help.
As the old saying goes, if it was easy anybody could do it............. Take careful note of my suggestion to put a lamp on to the circuit to test load-carrying capability. If you simply use a multimeter on the resistance scale the current going through the wire is almost zero, so if just one small strand is hanging on by a thread it will still show as "good" but will be breaking down under load. On the other hand if you use a 60W lamp there will be 5A going through the wire, a much more representative current-carrying test.
i do not know when i will get to this....it is not a priority.....and i will for sure need some inspiration, motivation, and lots of patience before tackling it. Thanks again.
so......i had a little inspiration this morning and started from the beginning and tested the continuity on the high speed switch and it seems like there is none this time. i cannot seem to figure out how to get at the switch....it looks like there is a cap on the top but it is not easily removed and i do not want to damage it. thoughts?
i feel a little stupid that this potentially is the problem.
Post a photo of what you're up against.? It appears as though the 319-6438 Switch is available as a service replacement. See attachments.
do you have an exploded view to see how it comes apart? i snipped the wires (which are easily soldered back together ) to confirm that it is the switch that is the problem.
i was able to pop off the greg thumb switch but cannot see how the assembly is removed from the knob.
grey thumb switch....not greg.
so in this part number (319-6438) does that include the whole knob assembly, switch, etc.? this would make sense because it does not look like it comes apart in order to be serviced. i can certainly call my cat dealer now and see what that replacement part costs.
Never having had one if these switches in my hand before I can't help you much regarding exactly the head of the lever is supposed to come apart to access the switch.
sure thing....i can certainly take it from here. thanks again.
looks like Cat will only sell the entire assembly including the metal arm that goes to the floor....$500.....for a faulty switch. My machine has less then 750 hours and is stored inside. Anyways, i am going to mount something aftermarket to the side of this existing switch.
That's ridiculous. The whole purpose of annoncing the serviceable parts was to give owners other repair options apart from replacing the lever complete. It appears to be available aftermarket - https://avspare.com/caterpillar/thumb/3196438/ and it's on Cat Parts Store.........
oh ya...you are going to love this....i used that part number and at cat it only references the grey plastic toggle piece your thumb touches....not the actual switch.....see photo....$66( i am in the wrong buisness)....for a piece of plastic. awesome. anyways, i rigged up a switch to the side of the existing switch which will for sure get me by for now. i can get these switches for under $10 and swap them out in 10 min. I will send a photo later(maybe tomorrow) of my work...do not judge
it is not pretty....but it functions. whenever i sell the machine if the new owner finds it important to have the OEM switch they can spend the $500.