Decent wiring diagram for 3CX ?

Scraperman

Scraperman

Well-known member
I have looked for this on this site but can't find what I am looking for and wondered if anyone could help me please ? I have a 2003 JCB Project 8 3CX, serial No. 412168, and the wiring diagram that is in my service manual is very poor in terms of clarity. I have downloaded it and used Photoshop to enhance it but it still isn't very good as can be seen below. I can print it out in A3 which will improve it I think. I obviously have the index page as well but that is O.K. There doesn't seem to be any colour codes for the cables.
My question therefore is if it is possible to find a better version elsewhere that I can download ?
WD-WIP-2.jpg
 
Scraperman

Scraperman

Well-known member
Also 2003 isn’t project 8..?
2003 will be a p21.. with the last of the Perkins engines.
Oh crikey, I always thought that it was a Project 8. Sorry about that. Here is my ID plate :

IMG_3871-cropped.jpg

The reason for my question is that I have a problem which I am hoping isn't going to be too tricky. My starter motor started to turn the engine over rather slowly about 12 months ago and I thought that it was the battery and so I bought a new one. But that didn't solve the problem but because the old girl is a good starter and always eventually starts I left things alone. I should say here that I am nearly 80 years old and struggling a bit with things that used to come easily. I bought my first JCB in 1969. However, the other day the starter just wouldn't turn the engine over fast enough for it to start and so I decided that I needed some help. I got out of the cab, with keys in my pocket, and suddenly the starter motor started. Only the actual motor, the solenoid hadn't pushed it into the flywheel. I quickly took the positive lead off the battery and the starter motor stopped. But as soon as I even touch the battery positive terminal with the lead the starter motor will start turning, still without the keys anywhere near the ignition switch.

I have had to get a mechanically-minded friend to come and help me and of course the front bucket is on the ground and so it would be a terrible job unless I can get the loaders arms out of the way. I have ordered a new starter motor but my concern is that there may be other issues somewhere, i.e. burnt out wiring or something like that. That was my reason for asking for a clearer wiring diagram.

The reason for
 
Scraperman

Scraperman

Well-known member
Don’t worry too much about the wiring diagram - I suspect help will be along shortly!…..
Although my friend is very knowledgeable about all things mechanical I am concerned that there might be more to it than just a new starter motor.
 
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DaveDCB

Well-known member
Yes I’d say a new starter is a good first port of call..
it could well be the starter relay is also sticking I wonder, causing the starter to keep firing with no keys.. it’s in the panel under the front bucket control levers in the cab. That era were always having dicky relays and fuses blowing!
 
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DaveDCB

Well-known member
I had a p12 3cx which had the same engine as yours, I put a new starter on that and lost my spanner behind the alternator.. oneday a happy Jamaican will find themselves a free spanner (that’s where that machine went to after I’d done with it 😁)
 
Scraperman

Scraperman

Well-known member
Yes I’d say a new starter is a good first port of call..
it could well be the starter relay is also sticking I wonder, causing the starter to keep firing with no keys.. it’s in the panel under the front bucket control levers in the cab. That era were always having dicky relays and fuses blowing!
Thank you for your continued help, I really do appreciate it. I didn't know there was a panel under the front shovel control levers. I'll have to have a look tomorrow.
 
Scraperman

Scraperman

Well-known member
I had a p12 3cx which had the same engine as yours, I put a new starter on that and lost my spanner behind the alternator.. oneday a happy Jamaican will find themselves a free spanner (that’s where that machine went to after I’d done with it 😁)
It certainly looks a pig of a job to replace the starter motor but I am trying to find a way to get the loader frame up in the air. I do have the semi-circular device that straps onto one of the lift rams when fully extended which I do use occasionally if I'm working in there but while I have tractors none have a loader on them and although the digger is inside a modern type farm building I wouldn't want to pulley block it up from one of the beams. I can take the front bucket off and tow it out of the way and I had a thought today about using various size acrows to jack it up once the bucket was off.
 
Scraperman

Scraperman

Well-known member
I was watching a video about a poor starting jcb telehandler the other day, apparently geared starters are the way to go instead of standard replacements. @ACEngineering sells them I believe
Thank you for that but I have already ordered a replacement starter motor. I did try to find a web site for ACEngineering but couldn't find anything.
 
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DaveDCB

Well-known member
Next time you go to start it, get someone to give the solenoid on the starter a smack with a hammer while your turning it over, there’s a good chance it might persuade it to engage!
 
Scraperman

Scraperman

Well-known member
Next time you go to start it, get someone to give the solenoid on the starter a smack with a hammer while your turning it over, there’s a good chance it might persuade it to engage!
Thank you. I wondered if that would work but the problem is that as soon as I connect the battery the the starter motor spins immediately and I'm not sure if it is a safe thing to do. But I will bear it in mind anyway. Thank you.
 
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