287B Quick Coupler & POS SELF LVL Blowing Fuses

[Urbanengineer]

Hello all. Chasing an issue where I keep blowing Hydraulic Quick Coupler/Self Level fuses after a machine washing. Had a couple inches of dirt in the pan. Can't use the machine much at all without functional attachment pin control (hard to bypass too).

On this B series machine, the Quick Coupler Switch and Positive Self Level Switch are factory spliced together in the LH Panel Harness before the connection 12 for the upper platform Harness P-C2 (electrical diagram). I assume my issue is related to water in connector 12 or somewhere upstream from there. I cleaned (electrical parts spray and dielectric grease) random plugs I could easily find under the cab. I also cleaned up the connections at the back of the skid CONN 24, AKA (11) QCPL SOL [solenoid] and CONN 1 aka WC-C1. I haven't found this Upper Platform Harness Connection yet. Would appreciate help with that.

Circuit Upstream wiring code: 117-A77 YL -18

Possible Issue Connectors:
Conn 15 (117-A77 YL -18 A-C11 becomes 117-PA105 YL -18 PA-C14, have not id'ed), [
Fuse Block 1 (cleaned and greased), [accessible with cab down, cleaned and di-e greased all connectors and fuses]
Conn 12 (PA-C2 #3, have not id'ed says to see C-C21 (LOC SH 2 H-15) OR CN-C21 (LOC SH 2 H-11) ) [Shows at cab height at rear pivot of cab]
Conn 1 (cleaned and e greased),
ACPLR Sol Valve (S1, S2 Connectors (cleaned and e greased)

Any idea on what is going on here?

B Series Electrical System Schematic Part Number: 216-6423, Change:02 AND Media Number: RENR6419-06

 

[Urbanengineer]

Connector 12 looks good (30 wires or so)


Connector 15 was also clean. Shown e greased up.



Started up and blew fuse again as previously. Going to try and run without connector 15 in and see if that fixes the instantly blowing fuse after starting and running without operating the switch(es).

Per nige’s recommendation, this should isolate a potential short to ground to a section of the harness. More later if I have time.

 

[Urbanengineer]

Some photos of the rear hydraulic manifold and solenoid mentioned in the first post below.



Also the main hydraulic manifold with oddly designed vertical plugs.





Circuit 14 is for self level and coupler. Cleaned fuse box pic. They really don’t have a sealed cover for this?

 

[Urbanengineer]

Can’t post a video, but the wc coupler works when this self level switch is on. This is the one that’s spliced together in the main chassis harness. Cant explain that.

What a picture can’t show is all 6 dash lights on the LH cluster flash momentarily when the QC button is pressed. Once I switch the self level off, then press QC in or out, it flashed ONCE and stopped moving QC pins.

 

[Nige]

This is the one that’s spliced together in the main chassis harness. Cant explain that.

Dead simple. The two switches have a common power feed taken from a single fuse. The splice is in that power feed where one wire (from the fuse) becomes two wires, one going to each switch.

If you want to show a video then you have to host it somewhere else such as YouTube and then link it in a post.

 

[Urbanengineer]

Gotcha. I can disassemble the switches next, but figured you all would want to see this. Unusual issue.

In my experience with LED lighting issues, I assume a small amount of voltage is leaking to ground. LEDs will light temporarily or ever so slightly with the lowest of voltage passing through a ground.

 

[Urbanengineer]

Fuse blows in the above video exactly the first time after pressing the QC switch with the self level switch in the off position (00:10, notice the LED's only flash once, first press, not the second?).

This is a new to me machine. I’m not certain if that self level switch was on from the testing or not, but this issue only appeared after a machine wash. I assumed that it was from the wash, but it was probably just me hitting this switch without realizing with my booger pickers and now having this issue. Now I see why older folks got flustered when I pressed buttons too fast .

 

[Nige]

You would benefit in having an Operation & Maintenance Manual so that you can identify what's supposed to happen when you press that switch. Cat Publication reference SEBU7732. Try this one from eBay.

Looking at the video I suspect there may be a problem downstream of the QC switch. TBH the electric quick coupler is not a very reliable piece of equipment. Try popping the switch out of the panel and unplug it from the cab wiring harness then see what happens regarding blowing fuses.

EDIT: Or try unplugging CONN 1.

 

[Urbanengineer]

I've got the digital copy of that operations manual and it has been useful learning the machine and how it responds to the many buttons it has to be pressed. It mentions nothing about it's relationship with the self level function, unfortunately.

Connector one is at the rear of the machine. I cleaned those connections with electrical parts cleaner and then di-elec greased the connections after they dried. I can try unplugging Conn1, but it will definitely shut down the qc switch is my concern.

The machine is currently working, but hasn't blown the QC fuse since I set self level ON.

Unrelated - I wanted to pull the floor pan and foot pedal too, but the foot pedal will not let that happen. It wont bend, twist, etc to go through teh hole on teh floor after removing bolts. holding it down. Any advice? Need to replace throttle cable.

 

[Nige]

The machine is currently working, but hasn't blown the QC fuse since I set self level ON.

Try unplugging the connector for the self level and see if you can set the switch to OFF without blowing fuses.

 

[Urbanengineer]

Okay I’ll find that and disconnect it. Good idea to see if that pops a fuse, if the circuit still lights in on it could be an internal short in the dvtr valve

 

[Simon C]

Some photos of the rear hydraulic manifold and solenoid mentioned in the first post below.

View attachment 360459

Also the main hydraulic manifold with oddly designed vertical plugs.

View attachment 360460

View attachment 360461

Circuit 14 is for self level and coupler. Cleaned fuse box pic. They really don’t have a sealed cover for this?

View attachment 360462

Was reading this entire problem and would like to mention that somehow you have been misinformed about Die-Electric grease. I seen it in some of your dirty plug receptacles and on other plugs, and if you look it up on the internet there is too many explanations to mention that highlight that it is a NON-Conductor. That means it is like a piece of wood and will impede electicity especially between pins. Might be an idea to do some research on this. There is some compounds that are conductors, but Die Electric Grease is not one.
A local dealership here had to get a whole pile of plugs apart and cleaned cause an owner decided to fill all the plug ins with Die Electric Grease. Very hard to wash out by the way, as I have had to clean a plug on a trailer that the lights were non- functional that was full of the exact product.

I had to look it up myself to find out my original info was wrong. It is good on the outside of a plug to prevent corrosion getting in but no good in between pinned connections.
Just to let you know a loose relay holder will increase currrent in some applications and cause a supply fuse to blow. Any relay with 4-5 pins only needs one pin to be loose to cause heat and more problems. Very hard to feel without testing every female pin receptacle before installing a relay.
Simon C

 

[Urbanengineer]

Okay, appreciate your experienced reply to both.

I’ll check the relays connected but that does make sense why it may not have also popped immediately sometimes (especially if I can’t find a short to ground on the Self Level / QC circuit.

 

[Nige]

Did you get any further with this.?

 

[Urbanengineer]

Finally got some more time to work on the skid. Needed to replace the long broken throttle cable.

The two ECU's under the floor pan were halfway covered in hydraulic fluid drips, dirt, and other forest debris. Probably my issue. Was not able to get the pan up before I fixed my throttle cable issues, but hoping a clean out and wash will fix this issue.

Was able to repair the main throttle cable, but the hand throttle cable is still acting up. Previous owner had the hand throttle disconnected and I can't figure that out. Fine with foot only for now.

 

[Simon C]

If I remember correctly, your ECM's are on the left side down under. They are bad for getting dirt behind, that will start to rot out the aluminum case. If I remember correctly they had a small ground strap coming out of the case. Muck out by hand first is my first suggestion to limit the amount of water getting to those ECU's. Some owners did post pictures of the back sides rotted right through in the past.
Need to clean up and re-examine.
Simon C

 

[Nige]

The two ECU's under the floor pan were halfway covered in hydraulic fluid drips, dirt, and other forest debris. Probably my issue. Was not able to get the pan up before I fixed my throttle cable issues, but hoping a clean out and wash will fix this issue.

If a clean out & wash fixes this issue I suggest that you should buy yourself a lottery ticket.

 

[Urbanengineer]

Good to know . I can live with this work around, I certainly would prefer to keep OFF the auto level though ha.