JCB 215 Ground/Earth Problem

[Dan603]

I have a 1995 or 6 JCB 215 Series 2. There has been a problem with the ground/earth for instruments in the console prior to me owning the machine. I am the second owner. I recently replace the radio and found that it will turn over but not start now and I have some lights on the console illuminate that didn't before and are not prestart alarms. I think that the issue is a bad ground/earth. I checked the manual and each numbered wire to be certain that it was properly wired and it is. My manual does not show the grounds...

Does anyone know on the chassis where the ground wires for the console are attached?

Thanks.

 

[Bls repair]

How many wires did you disconnect. How many spade type connectors ,how many ring type connectors.

 

[Bls repair]

Sorry wrong post.

 

[LN Pipeline]

If you have a service manual, the grounds are listed in Section C, 41-5. Later serial numbers are a few pages later. All ground wires are labeled 600 something.

I had all sorts of electrical problems with my 214. Most of them came from the main wiring harness wearing through and rubbing on the transmission. This was the main harness that came off the starter and went under the right side of the cab. Very hard to get at.

I also had issues with my instrument panel. It ended up being a partially melted fuse. It tested good with the tester, but apparently wasn’t allowing enough amps to the dash. Replaced it and everything started working.

While trying to find my electrical problems, I found my alternator prongs were severely corroded. Cleaned them before I found the wiring harness - don’t know if that was giving me problems or not.

There is a guy on here named JCB Jeff, who is very knowledgeable of JCB equipment. Maybe send him a message.

 

[Dan603]

Thanks LN. Mine is one of the 430001 or higher serial numbers. I see the table and wire numbers and effected harnesses. What I am wondering is where the wires actually terminate to ground/earth. I am expecting to find corrosion at that point. I wasn't able to locate it under the machine, console, or the engine compartment. I guess I will have to take the engine cover off of the top and see if it is somewhere near the battery. That would be a logical place...

 

[jcb jeff]

Check the earth between chassis and engine this will be at the back of the engine block /gearbox joint area.
Also check the wiring harness plug that comes up through the chassis into the cab at the base of the front loader control lever area for corrosion or damaged pins.

 

[Dan603]

JCB Jeff: Thanks for the tips.

I checked both of the harness connections near the loader control lever area and they were very clean! Not bad for an almost 25 year old machine. Since I had the console partly disassembled I checked the two near the base of the seat. Both of the harness connections were surprisingly clean. There was a plug, however that had four of the six wires leading into it compromised. It looks like the mice chewed the sheathing off of the wires. Nothing was actually plugged into the socket underneath the machine so I cut the plug out, heat shrinked, and taped the wires. The plate that they were attached to was partly rotted and I removed the old plug and sealed the hole. The machine turned over but would not start. No change, but the wiring was definitely a problem.

I followed the harness to see if I could locate where the grounds terminated and attached to the machine. I found another wire with split sheathing and casing. I think it was a transmission sensor plug. I have to identify it for certain and get a replacement. I have noticed the transmission fluid warning flicker on and off and this is a likely cause.

I did find the negative terminal cable and where it attaches to the back of the engine. I think, hope I can get to it by pulling the plate on the front of the cab, where the steering column passes from the cab to the underside of the tractor. At that point I ran out of daylight and had to call it a night.

I am still looking for where those ground/earth wires, the 600 and 700 series terminate...

 

[jcb jeff]

All 600 wires are earths

 

[Delmer]

there's usually nothing special about where the grounds terminate.

I like to add more grounds, like if I'm replacing a ground cable from the battery, have one heavy cable go to the starter bolt, one medium cable to the engine block and one medium cable to the chassis. If you're thinking your cab/dash is the problem, add a 10 gauge ground from the battery cable to the chassis, then to the cab, and then to the dash if there's anywhere metal to ground to, then add connections to a couple points in your harness where you can identify the ground. You don't need bigger cables than the wiring harness, but it doesn't hurt. The main thing is clean connections to ground everything.

If it cranks OK, then the negative battery cable is OK, you can test the voltage drop while cranking if you want too.

 

[Dan603]

I found another badly frayed wire. I think it is for the transmission oil pressure sensor. I got an alarm there periodically and this may explain why.

 

[Delmer]

The color of that wire looks like it shorted with too big of a fuse and overheated the wire. Usually the insulation looks melted too. That insulation looks like it fell apart without melting, from here anyway. If it overheated, that would tell me to look everything over better, which is what you're already doing.

 

[Dan603]

I am planning to add grounds as Delmer suggested. It certainly can only help. But what seems different from a passenger vehicle is that each circuit from the side console seems to have a wire that leads to ground/earth rather than just grounds going to a console ground or chassis. I imagine it was built that way to avoid ground issues due to failed connections between chassis, cab, engine, etc...Those wires have to get to the negative battery terminal somewhere, somehow. Since the negative terminal is bolted to the back of the engine, the earth must terminate somewhere. That's what I am looking to find, where they terminate to get to the negative...

 

[Delmer]

I'm not familiar with JCB, it's not uncommon for the harness to have grounds to some/most circuits. What I've seen in other makes is the harness has ground screws at various places like I mentioned.

Putting all your grounds through the harness with failing grounds to the chassis is infamous for doing strange things, and lots of pulled out hair for mechanics. If everything grounds to the chassis without harness grounds, same deal, just a little more straightforward in my mind

 

[Dan603]

As Delmer predicted. I was able to locate the plug that the wires were attached to. It was the transmission pressure sender. I removed the plug and moved it into a better position to see it. As you can see, it is smoked! I went through all of the fuses and found a 30 amp fuse in place of a 10, and another in place of a 15. I will get in touch with the local JCB dealer for a replacement plug. I may end up running new wires along the harness to the console rather than trying to get into the harness as the wire is cooked back toward the harness and it is a challenge to get to anything where this is located.

 

[Dan603]

I replaced the plug today, soldered, shrink tubed, wrapped and taped the wires into the harness. The backhoe started right up and ran fine. I had no chirps from the transmission pressure warning. Thank-you all for your advice. Additional grounds to follow as time permits.