Couldn't really find any threads that were particular to my situation. Cranks but very slow. What I have done so far. Drained old fuel and replaced with fresh fuel. Replaced fuel filter and bled air. Replaced battery and starter. Replaced battery cable ends. Still cranks slow. Use to be able to jump it to get it started but that doesn't even work now. Any other areas I could check? My next idea was to replace both battery cables. Something is drawing the battery from 12.8v to 9.8 when you turn the key. Any help would be appreciated. Thanks
I'd check the other ends of the battery cables. Try putting jumper cables directly on the starter to see if that makes a difference. Then that will show you have a wiring issue.
Does yours have a batt isolator if so link it out ,also check earth lead on engine block and make sure no hydraulics are loading up on cranking
Totally thought this was the problem. These are the wires coming out of the little 5 fuse box that connects to the positive terminal of the battery. Replaced all the fuses in that box too. Unfortunately it made little change to cranking. Also checked and cleaned all the grounds today with little return for my efforts. Did get it to run finally but it's really hard to start and takes a lot of cranks. Volts still dropping from 12.8 to 9.8v when cranking
Do you have jumper cables? Connect from your battery to the starter. If that don't make a cranking difference, connect from other vehicle, and to the battery. See how it cranks. Then connect to the starter. You need to rule out the wiring is bad or not. Then rule out the battery, and ultimately the starter.
Yes, I have a commercial charger that has a jump feature. I hooked up the jumper cables to the starter and made no cranking difference.
Jump feature charges the battery. It doesn't act like a battery. You're doing it wrong.
Did you replace the starter as some starters are better than others ,has this got a RJ build perkins engine in. If you have the perkins RJ there is a glow plug relay box in the engine bay which could be an issue just depends on engine have you a serial number?
What voltage you got at the solenoid wire to starter ,try triggering starter from the battery pos on the starter with a jump wire and see if that changes anything.
Oh sorry. I thought the jump feature was like jumping starting from a vehicle. I will first try taking jumper cables from its own battery and connect to the starter. Then I will connect from another vehicle to the jcb battery and see what happens. Then connect to the starter and see. I'll report what I find. I have a rebuilt AIS starter for it. Serial number is AR50656U009934D
The trigger wire for the starter solenoid so the smaller wire at the starter. Pull the that wire from solenoid and give the terminal that you removed the wire from 12 volts from the the machine battery and see if that makes a difference as you are by passing every thing up stream of the starter. Was this fault the same with old starter as well as new starter any improvement. Other thing to check as i said before is to make sure that hyd circuit is not loading up ,perhaps try using the crowd dump lever whilst trying to start.
So I noticed the one of the grounds on the starter getting really hot when cranking in a short amount of time. This cluster was connected to the negative terminal on the starter. I disconnected and the starter wasn't getting as hot and the volts were only dropping to 10.6v now and not 9.8v. Any idea where this cluster is suppose to connect to?
I tried what you said with little wire from the starter with no change in cranking speed. Sorry for the dumb question but what is the crowd dump lever?
Also this thing has been cobbled by many different mechanics before me. Can anyone tell me what the correct battery is for this piece of equipment? I just want to make sure the mechanic before me put the correct one in. Thanks
I think it should be around 1000cca. You can pick up at farm stores.
Those yellow wires were connected to that ground stud out the back of the starter? I know nothing about JBC, but it's British? I've never seen any Brit vehicle with anything but black for grounds. Is that a rebuilt starter on there? Lucas? Is that the rebuilt you said you had, not clear if you have one or you installed one. Joe H
Those wires bolt to the stud on the end of the starter i believe. They can probably bolt to any ground. And you can buy new starters for $100 on ebay. You can find many common jcb parts on ebay.
Ok so here is an update guys. Those wires connected to the negative terminal on the starter was smoking the other ground on the starter. Turning then it red hot. After disconnecting them voltage drop at the battery when cranking was going down to only 11.0v instead of 9.8v. Still can't get it to start just off the battery alone but now I only have to put the battery on the charger on it for a few minutes and it was firing right up today. I'm thinking I need a better battery. I was thinking this one. Any thoughts?
Are those yellow wires hot when the key is on? Hot in the crank position only? Never hot? You don't have a wiring diagram I guess? Joe H
I do not have a wiring diagram. I assuming they are hot since they come out of the harness that is attached to the positive terminal on the battery.
purchase or download the service manual for your machine and stop guessing...they're worth their weight in gold and make your life much easier....
A guy sent me a pdf file service manual that I'll look over on Monday when I get to work.
Atta boy, you'll be glad you did..over the years I don't care if it was a Chiltons manual for a pickup or car repair, an old manual for tractor fixin' or even a stinkin' riding mower if you have "the book" the knowledge is at your finger tips....
You don't need a wiring schematic to figure your slow starting. You have ground and positive from the battery. I assume your positive cable goes direct to the starter. Where does the negative battery cable go? It should be bolted on the engine block. And my last two jcb used 29h size battery.
The voltage drop and the red hot wires indicate that something is wrong with his wiring,he also stated that several people have hacked into the works before,and from the picture he posted it looks like he's got connectors hacked into his connectors... wiring diagram may help isolate previous indiscretions.....just saying.......
Mrclean, you didn't maybe accidentally pinch a wire when you put the starter or some other part back on did ya? some kinda short is usually what makes wires glow....P.S. if you're going to pursue the mechanic thing,learn how to decipher the diagram....not shaming,just a suggestion...Stinky
You don't need an expensive AGM battery. A 1000cca lead acid would cost about $100.00 at any autoparts store. Just sayin.
It's not that complicated. Every engine with a starter has a positive cable to the starter solenoid and a ground cable to the engine block. He has not answered where his negative battery cable goes or where it's bolted to. If his engine ground is off, he may grounding thru the bunch of yellow wires, hence getting hot and not cranking good.
Instead of just throwing parts at this concern why not diagnose what is wrong? First measure the voltage at the battery when cranking. If under 10.5volts or so your battery is no good. If at or above this replacing your battery is not going to solve your problem. If the battery voltage during cranking is normal then measure the voltage drop to your starter. Put the meter on the positive terminal and the starter positive connection, crank engine and note the volt reading. Do the same on the negative terminal and the starter body. If either of these are more than .5 volts you found your problem. The fact you state the wires get hot proves you have unwanted resistance in the circuit. Measuring voltage drop is basic diagnosis for this type of issue. High current circuits with small unwanted resistance will be found by this method. Measuring resistance is not a good method. Use Ohms law and you will see a 2 volt drop in a 500 amp circuit is a tiny resistance that on a meter you would not suspect but you can see it using voltage drop.
The ground wire is grounded to the top of the engine. I had taken it off and cleaned it really well. I took some time off for Covid leave back in March and they had this hack mechanic take over when I was gone and he out a 1000 cca battery in it. I wonder though if that battery is shot. I did do a load test on it and it passed.
Just because you cleaned the connection does not mean the ground is good. Do the voltage tests I suggested. Three quick measurements and you will know what is wrong.
Where on top of the engine? On a rusty bracket? on something that is isolated by gaskets? like skata implied earlier the ground should be directly to the block..perhaps a spot where other grounds are connected.. maybe one from the frame to the block...
Mrclean ; You never answered jcb jeff's question in post # 3. Which was simply -- is the battery (earth connection) ground connected to the engine block ? I know you said that you cleaned the grounds. He also asked if you moved the crowd (dipper) control lever while cranking the engine. You didn't answer that, and it could make a significant difference in the cranking speed. Again that simply determines if the hydraulic pump is putting an additional load on the starting motor while it is engaged.
Three simple voltage measurements and the suggested test with control lever all take less than five minutes total. The voltage tests will rule out or prove there is a voltage supply issue. By day I am a field service engineer for a major auto manufacturer. I never understand the refusal to perform tests to diagnose an issue vs. just guessing and changing parts. My Cat was cranking real slow when I got her. In one minute I knew my issue was the ground cable not the connection. It had internal resistance causing a nearly 3 volt drop. A new cable and she cranked like a new machine.
Any 600 wire is and earth path so could be 600 or say 601 they are earths
Sorry guys had to work on other equipment yesterday so I didn't have a chance to do any of the tests. I will preform the 3 tests today and return with what I find. Also the main battery ground does ground to the top of the engine block. I completely removed and and inspected the cable. No corrosion of any kind.
Ok on the negative terminal with lead and other on the starter body the voltage was .5, jumped to .6 for a second. So does that mean my ground to the starter is bad?
You're only measuring .5v?? Also a cable may appear good, but could have internal corrosion on the connector ends.
Edgephoto said to try this If the battery voltage during cranking is normal then measure the voltage drop to your starter. Put the meter on the positive terminal and the starter positive connection, crank engine and note the volt reading. Do the same on the negative terminal and the starter body. If either of these are more than .5 volts you found your problem.
Oh. You meant .5v drop.
The .5v is when cranking, right? Now put the meter from battery negative to the ground point on the engine and crank. Note the voltage. Did you do the positive side? If not, do that. What was battery voltage during cranking? If you are losing .5-.6 volts on the ground side and same or more on the positive side you are providing 1-1.2 volts less to the starter. This could enough to cause a slow crank. try to measure the positive side where the power comes out of the solenoid.
Measure from battery positive to point 1 then at point 2. This way you also are testing the solenoid. you starter may look slightly different. If you aren’t sure post a picture.
Only negative side is dropping .5v Drop on positive side is only .1v
Here is the same material on running tests for checking the voltage loss (from the service manual for a 580 Case), the tests are universal to any machine, I believe.
Here's an interesting question. When I was working on the machine this morning I touched my work light that has a metal cage around the light bulb to the lift arm of the front loader by accident and it sparked. Do you think the machine is not grounded?? Never has any matching do that before so I know it's not normal.
I hope the cord in your work light has a neutral and a ground that is functional.
Doesn't arch on any other piece of equipment. My heat gun also arched when I bumped it against the front loader
Did you measure the positive at point 1 and point 2 in the picture I provided? Was it .1 volts at both points? What is the battery voltage when you are cranking? As far as your acing from you heat gun and drop light sounds like you have an issue with you electric. Bad ground or polarity is wrong.
Mrclean, although I'm not familiar with the ground setup on that machine , every commercial truck that i have worked on for the past 30+ years has had a central ground on the side of the block with several grounds, always 1 to the starter lug,one to the battery and 1 to the frame and the others to the ecu or other stuff .. if you're getting sparks from the loader try a good heavy jumper cable from a "good" ground on the block where your other ground connects to the loader frame even if you have to use vise grips for a good connection and see if it eliminates the issue...Did you actually try swapping out the existing ground cable with a good one from some other machine around there?
When I checked the positive side of the starter it was reading .1v When I checked the negative side of the starter it read .5 - .6v I'm going to try step 4 in the picture you sent me right now.
So I believe I have traced the problem to the negative cable. Whether it's bad or what I'm losing .5v thought negative cable. I'm not losing any voltage through the positive
It won't cost much to replace it, then you will know.
Yes you need to replace the negative cable at least. you still have not posted battery voltage during cranking.
Sorry I though I had posted it in my first post on this thread. Cranking voltage has varied from 9.8v - 10.6. sometimes it will drop to 9.8v and sometimes it will drop to only 10.6v.
9.8 volts is low. Combine that with a .5 volt drop on the ground side you are only getting just over 9 volts to the starter motor. Make sure the solenoid is not part of the issue by doing voltage drop for battery to point 2. If it is good repair the bad ground and install a good battery.
This is the a ground on the starter. The metal connecting the the points gets red hot. Thoughts?
Also I am assuming the crowd control lever is the front end loader control? When moving the control to lift the front bucket while cranking to start the engine the bucket does lift up while cranking. Should it move while cranking or is a hydraulic pump bad?
I think what Jeff was referring to is the ( button ) on the loader arm, it disconnects the hydraulics, its a black button on the stickshift. You shouldn't push the loader shifter forward while cranking, it won't help your issue.
The photo above,....it looks like that "could" be a live connection, it's hard to see in the photo. Are you sure that's a ground wire? Have you tried removing it and testing for voltage. Remove it and test the wire for continuity to ground.
The crowd (dipper) is the big arm on the backhoe that has the bucket hanging on it. The lever that controls it is the one I think he was referring to.
Sorry it's the metal piece that connects to the grounds in that picture. I will take a better pic once I get it out. Also I have conflicting engine tags. On the right intake it says perkins 3.9l. but when I searched it on Google I could only find perkins 4.2 Do they make a 3.9l? The tag on the left of the engine block says 1992.
Not to be a smart ass, but I think you need to hire a pro if you can't tell that is a positive point, not negative.
Well thank you but I did figure it out and starts great now. Thanks to everyone for all the help advice and trying to point me in the right direction.
So, what was the solution ? Other members will need to know if they have the same problem.
Well, we are waiting. What did you do to fix it.....?
Don't think the young man likes constructive criticism.......
I do hope he post's his findings. There are many with similar problems,.
Give us the engine code for your perkins, should be able to find out the type.
Can you post a follow-up to this? What was the solution?
He won't say. Probably something dumb and too embarrassed to say. Lol